The United States is the largest single financial contributor to the United Nations (U.N.) system. Congress plays a key role in shaping U.S. policy at the United Nations through funding and oversight. Each fiscal year (FY), Congress authorizes and appropriates U.S. contributions to a range of U.N. entities. In FY2017, the United States provided more than $8.5 billion to the U.N. regular budget, specialized agencies, peacekeeping operations, and funds and programs. Over the decades, congressional debates on U.N. funding have generally focused on three key issues: the appropriate level of U.S. contributions to the U.N. system; whether U.S. funds are being used effectively; and how changes in U.S. funding might further U.S. policy priorities in the U.N. system. Congress is currently considering President Trump's FY2019 budget request which, if enacted, would significantly reduce U.S. funding to U.N. bodies. This report provides an overview of the processes and mechanisms for U.N. funding. It discusses how the United States funds the United Nations and outlines selected U.S. contributions to U.N. bodies. The final section presents selected policy issues for Congress, including debates over U.S. assessment levels, the possible impacts of U.S. withholdings, U.S. arrears to the United Nations, and the relationship between U.S. funding and U.N. reform. The United States is one of the founding members of the United Nations and continues to play a lead role in the organization today. U.S. participation in and funding of the United Nations is authorized through the U.N. Participation Act of 1945, as amended (22 U.S.C. 287 et seq.). Both Congress and the executive branch shape U.S. policy toward the organization. Congress authorizes, appropriates, and oversees U.S. funding to the United Nations, while the executive branch represents the United States in U.N. bodies through the State Department and the U.S. Mission to the United Nations (USUN). The President nominates Ambassadors for U.N. posts, and the Senate provides advice and consent for executive branch nominees. USUN is led by Ambassador Nikki Haley, the current U.S. Permanent Representative to the United Nations. The United States is a member of several key U.N. bodies. It serves as one of five permanent members of the Security Council (with veto power over Council resolutions), along with China, France, Russia, and the United Kingdom. It is also a member of the General Assembly and 12 specialized agencies. The United States is often elected to leadership positions on U.N. boards, councils, and other entities. Members of Congress hold varied perspectives on the appropriate level and extent of U.S. funding to the United Nations. Generally, Congress supports the United Nations and its overall mission; it provides funding to U.N. bodies each year, and often uses U.N. mechanisms to further U.S. foreign policy objectives. In FY2017, the last year in which comprehensive information is available, U.S. funding included $1 billion in assessed contributions to the U.N. regular budget and specialized agencies; $1.9 billion in assessed contributions to U.N. peacekeeping operations; $295 million in voluntary contributions to U.N. funds and programs; and $5.6 billion in voluntary contributions to U.N. humanitarian-related entities ( Figure 1 ). At the same time, some policymakers have been critical of the United Nations, especially when they believe U.N. actions may not align with U.S. policy priorities. Many Members have also expressed frustration with U.N. bodies or activities that, in their view, are not operating efficiently or lack effective accountability mechanisms. Over the years, Congress has sought to address the aforementioned concerns by raising or lowering U.N. funding levels and placing financial conditions or limits on U.S. contributions to U.N. entities. Some Members have also proposed eliminating all U.S. funding to the organization or providing only voluntary, and not assessed, contributions. In addition, Congress conducts oversight of U.N. funding by holding committee hearings, enacting reporting requirements, or consulting with executive branch agencies. It also queries executive branch nominees for U.N.-related posts, and can investigate U.N. entities or activities funded by the United States. The U.N. system is made up of interconnected components that include specialized agencies, voluntary funds and programs, peacekeeping operations, and the U.N. organization itself. Article 17 of the U.N. Charter requires each U.N. member to contribute to the expenses of the organization. U.N. entities are financed largely by contributions from members, which are made through two main channels: assessed and voluntary contributions. Members of U.N. entities are assessed a percentage of the organization's total budget. These assessments, which are determined by the members of each organization, provide U.N. entities with a regular source of income to staff and implement authorized programs. Payment of such contributions is a treaty obligation accepted by a country when it becomes a member. The U.N. regular budget, U.N. peacekeeping operations, and U.N. specialized agencies are funded mainly by assessed contributions, although some of these entities also receive voluntary funding. U.N. members pay assessed contributions to the U.N. regular budget, which funds the core administrative costs of the organization. The regular budget is negotiated and adopted by the General Assembly for a two-year period, or biennium, and is usually revised mid-budget period to reflect new programs or other changes. As outlined in the U.N. Charter, budget decisions are made by a two-thirds majority of members present and voting in the Assembly, with each country having one vote. Since the late 1980s, however, decisions related to the budget have, with few exceptions, been adopted by consensus. The approved U.N. regular budget for the 2018-2019 biennium is $5.39 billion (about $2.7 billion per year). The U.N. General Assembly negotiates a scale of assessments for the regular budget every three years based on a country's "capacity to pay." The Assembly's Committee on Contributions recommends assessment levels based on gross national income and other economic data, with a minimum assessment of 0.001% and a maximum assessment of 22%. The United States is currently assessed at 22% of the regular budget, the highest of any U.N. member state. Other top contributors include Japan, China, Germany, and France; the largest 12 contributors account for nearly 75% of the total regular budget ( Figure 2 ). The Assembly is expected to adopt new assessment rates for 2019 through 2021 in December 2018. There are currently 15 specialized agencies in the U.N. system, including the International Atomic Energy Agency (IAEA) and the World Bank Group ( Figure 3 ). Each of these entities is a legally independent intergovernmental organization with its own constitution, rules, membership, organs, and financial resources, including scale of assessments. Some agencies follow the assessment levels for the U.N. regular budget, while others use their own formulas. The United States is a member of all specialized agencies except for the U.N. Industrial Development Organization (UNIDO) and U.N. World Tourism Organization (WTO); it is currently in the process of withdrawing from the U.N. Educational, Scientific, and Cultural Organization (UNESCO). U.N. members provide assessed contributions to U.N. peacekeeping operations. These operations undertake activities related to cessation of armed conflict and postconflict assistance. As of early 2018, there are 14 U.N. peacekeeping missions worldwide with more than 100,000 military, police, and civilian personnel from over 120 countries. The United States, as a permanent member of the Security Council, plays a key role in establishing, renewing, and authorizing funding for such operations. U.N. Security Council resolutions establishing peacekeeping operations specify how each operation will be funded. In most instances, the Security Council authorizes the General Assembly to create a separate special assessed account for each operation that is funded by contributions from U.N. members. The total approved budget for U.N. peacekeeping operations for the current year (July 1, 2017, to June 30, 2018) is $6.8 billion. The General Assembly adopts the peacekeeping scale of assessments every three years. The scale is based on a modification of the U.N. regular budget scale, with the five permanent U.N. Security Council members assessed at a higher level than they are for the U.N. regular budget ( Figure 4 ). The U.S. peacekeeping assessment of 28.43% is the highest of any U.N. member. (Since the mid-1990s, Congress has capped the U.S. assessment at 25%.) Other key contributors to U.N. peacekeeping include Japan, the United Kingdom, and Germany; the top 10 contributors account for about 80% of total peacekeeping assessments. Voluntary contributions finance special funds, programs, offices, and other entities of the U.N. system ( Figure 5 ). No member is required to provide such funding; governments may decide what, if any, contributions will be made during each budget cycle. Many U.N. entities such as the U.N. Development Program (UNDP), U.N. Children's Fund (UNICEF), and U.N. Environment Program (UNEP) depend on voluntary funding; consequently, their budgets may fluctuate from year to year. Depending on donor preferences, contributions might be used to fund the core budgets of these bodies or may be earmarked for specific activities. Congress has generally authorized the majority of assessed and voluntary contributions to the U.N. system as part of Foreign Relations Authorization Acts, with appropriations provided to the Department of State and U.S. Agency for International Development (USAID) to meet obligations. When authorization bills are not enacted, Congress has waived the authorization requirements and appropriated funds through U.N. and U.N.-related accounts in annual Department of State, Foreign Operations, and Related Programs (SFOPS) appropriations acts. In some cases, U.S. contributions to U.N. bodies might be funded through other appropriations acts. A number of congressional committees are responsible for overseeing different aspects of U.N. funding. Authorizing committees include the Senate Committee on Foreign Relations and House Committee on Foreign Affairs. Most U.N.-related appropriations fall under the jurisdiction of the State-Foreign Operations Subcommittees of the House and Senate Committees on Appropriations. Some U.N. activities—particularly those related to global health, labor, defense, or the environment—might fall under the jurisdiction of other authorizing and appropriations committees such as Labor-Health and Human Services, Interior and the Environment, or Defense. Most U.S. funding to the United Nations is authorized and appropriated to the State Department or USAID through annual SFOPS appropriations acts. Some U.N. entities are funded through more than one account, and organizations with assessed budgets might also receive U.S. voluntary contributions. SFOPS funding can generally be divided into four categories. A ssessed contributions to the U.N. regular budget and specialized agencies are funded primarily through the State Department's Contributions to International Organizations (CIO) account. Congress generally appropriates a lump sum to CIO based on estimates of U.S. assessments. A ssessed contributions to U.N. peacekeeping are funded mainly through the State Department's Contributions for International Peacekeeping Activities (CIPA) account. Congress usually appropriates a lump sum to CIPA based on projected peacekeeping operations budgets and U.S. assessments. V oluntary contributions to U.N. funds and program s are funded through the International Organizations and Programs (IO&P) account. Congress usually specifies funding levels for each U.N. organization in enacted SFOPS bills or in accompanying reports or explanatory statements. V oluntary contributions to U.N. humanitarian-related entities are funded through the global humanitarian accounts, including the State Department's Migration and Refugee Assistance (MRA) and Emergency Refugee and Migration Assistance (ERMA) accounts, and USAID's International D isaster Assistance (IDA), and Food for Peace ( P.L. 480, Title II ) accounts. Congress generally appropriates overall funding for each of these accounts, while the executive branch determines how funds are allocated based on humanitarian needs and U.S. policy priorities. The process for authorizing and appropriating funding to the United Nations is sometimes complicated by several factors. Perhaps the most significant of these is the difference between the U.S. and U.N. fiscal years. The U.S. fiscal year (October 1 to September 30) does not align with the U.N. regular budget fiscal year (January 1 to December 31) or the U.N. peacekeeping fiscal year (July 1 to June 30). As a result, U.S. payments are often behind, and funding levels reported by the United States and U.N. system may not match. Other factors include modifications to U.N. budgets due to the practice of "recosting," periodic changes to U.S. assessment levels, unforeseen circumstances (such as the establishment of a new peacekeeping mission), and U.S. withholdings—each of which can cause funding shortfalls or overruns in U.N. or U.N.-related accounts. Additionally, since the 1980s the State Department has paid nearly all of its assessments on a deferred basis, causing some U.S. payments to be delayed by a year. For example, calendar year 2018 U.S. assessments will likely be paid with funds from U.S. FY2019. Over the years, Congress and the executive branch have sought to address these issues through a range of methods. To increase budget flexibility, policymakers have requested and allowed for multiyear funding for certain U.N.-related accounts. In some instances, they have also permitted the application of U.N. credits to outstanding balances, transferred funding to or from other accounts, or, when available, applied carryover funding from previous fiscal years. In other cases, Congress or the executive branch has declined to cover funding shortfalls, causing the United States to fall behind in payments and, in some cases, accumulate arrears to U.N. entities. An ongoing challenge facing U.S. policymakers is tracking and determining the full scope of U.S. funding to the U.N. system across all U.S. government agencies and accounts. There is no "one number" that represents total U.S. funding to the U.N. system at any given point in time. This is due to the complicated nature of U.S. and U.N. budget processes, the decentralized structure of the United Nations, and the range of U.S. government agencies, departments, and offices that, either directly or indirectly, fund various U.N. entities and activities. Over the decades, Congress has enacted several U.N. funding-related reporting requirements to help address this issue. While some have provided useful snapshots of U.S. funding during particular time periods or to select U.N. bodies, for a variety of reasons few have consistently or comprehensively captured the full scope of U.S. contributions to the entire U.N. system. Consequently, the U.S. funding described in this report represents the majority, but not all, of U.S. contributions to the U.N. system. This section outlines selected U.S. contributions to the U.N. system through annual State, Foreign Operation, and Related Programs (SFOPS) appropriations acts since FY2015, including the President's FY2019 budget request. In some cases, FY2017 funding levels are used as the main point of comparison because U.N.-specific FY2018 appropriations have not been finalized. In general, Congress appropriates lump sums to the U.N.-related accounts and does not direct U.S. contributions to specific U.N. entities, although it could opt to do so through line item appropriations or other enacted legislation. The Trump Administration has expressed general support for the overall mission of the United Nations. At the same time, President Trump has criticized the organization for its lack of effectiveness and argued that the United States contributes a disproportionate amount of funding to U.N. bodies. The Administration's FY2019 budget request appears to reflect these concerns. Specifically, it proposes a 25% reduction from enacted FY2018 funding for assessed contributions to the entire CIO account based on the expectation that U.N. organizations will "rein in costs, enhance their accountability and transparency, improve efficiency and effectiveness, and that the funding burden be shared more equitably"; a 13% reduction from enacted FY2018 funding for U.N. peacekeeping operations, based on the Administration's commitment to seeking reduced costs by "reevaluating the mandates, design, and implementation" of missions, and sharing the financial burden "more fairly" with other U.N. members; zeroing out voluntary contributions to U.N. funds and programs typically funded through the IO&P account, such as UNICEF and UNDP; and a 32% decrease in humanitarian assistance from FY2018 funding levels and the elimination of the Food for Peace (P.L. 480, Title II) and ERMA accounts, which could impact humanitarian-related funding to some U.N. entities. If enacted, the proposed funding levels for U.S. contributions to assessed U.N. budgets would fall short of actual U.S. assessments, causing the United States to fall behind in its payments and possibly accumulate arrears to U.N. bodies. The State Department's Contributions to International Organizations (CIO) account funds assessed contributions to 45 international and regional organizations, including the U.N. regular budget and U.N. specialized agencies. The United States is assessed 22% of the U.N. regular budget, while U.S. assessments to the U.N. specialized agencies vary by organization. For FY2019, the President requested $1.095 billion for the entire CIO account, a $372 million (25%) decrease from the enacted FY2018 funding of $1.467 billion. Of the FY2019 CIO request, $863.39 million is designated for U.N. entities. This represents a $193 million (or 18%) decrease from actual FY2017 U.N. CIO funding of $1.056 billion ( Table 1 ). If the President's FY2019 CIO request were to be enacted, the United States would likely pay less than what it owes to many U.N. entities, creating a funding shortfall in the CIO account and possibly leading to the accumulation of U.S. arrears in some U.N. bodies. For a breakdown of CIO account funding by U.N. entity, including U.S. assessment levels, see Appendix B . U.S. assessed contributions to U.N. peacekeeping operations are funded primarily through the State Department's Contributions for International Peacekeeping (CIPA) account, which includes most U.N. peacekeeping operations, the U.N. international criminal tribunals, and mission monitoring and effectiveness support funds. One peacekeeping mission, the U.N. Support Office in Somalia (UNSOS), is funded through the Peacekeeping Operations (PKO) account, which funds most non-U.N. multilateral peacekeeping and regional stability operations. Two others, UNTSO (Middle East) and UNMOGIP (India and Pakistan), are funded through the U.N. regular budget in the CIO account. For FY2019, the Trump Administration has proposed $1.19 billion for the CIPA account, a $186 million (13%) decrease from FY2018 enacted funding of $1.382 billion, and a $711 million (37%) decrease from the actual FY2017 contributions of $1.9 billion. In FY2017, CIPA funding declined by $553 million (22%) from FY2016 levels ( Table 2 ). According to the Administration, the FY2019 request is based on the expectation that the unfunded portion of U.S. assessed expenses "will be met through a combination of a reduction in the U.S. assessed rate of contributions, and significant reductions in the number of U.N. peacekeeping missions." Several policy changes account for recent declines in U.S. contributions to U.N. peacekeeping operations. The U.S. assessment for U.N. peacekeeping operations is 28.43%; however, since the mid-1990s Congress has capped the U.S. assessment at 25%—at times leading to funding shortfalls. Over the years, the State Department and Congress covered these shortfalls by raising the cap for limited periods and allowing for the application of U.N. peacekeeping credits (excess U.N. funds from previous peacekeeping missions) to be applied to U.S. outstanding balances. For several years, these actions resulted in full U.S. payments to U.N. peacekeeping; however, in FY2017 and FY2018 Congress declined to raise the cap, and since mid-2017 the Trump Administration has allowed for the application of peacekeeping credits up to, and not beyond, the 25% cap. The State Department estimates that the United States will accumulate arrears ($274.6 million in FY2017 and $251.6 million in FY2018) mainly because of these changes. For a breakdown of CIPA funding by U.N. peacekeeping operation, see Appendix C . Some U.S. voluntary contributions to U.N. entities and other international organizations are funded through the International Organizations and Programs (IO&P) account; examples include UNDP and UNICEF among others. Similar to its FY2018 budget proposal, the Trump Administration's FY2019 request eliminates the IO&P account and suggests that some unspecified activities currently funded through the account could receive contributions through a proposed Economic Support and Development Fund ( Table 3 ). For FY2018, Congress provided $339 million for the entire IO&P account, of which $296.2 million was for U.N. entities. Organizations that received the most funding include UNICEF ($137.5 million), UNDP ($80 million), and the U.N. Population Fund (UNFPA), if eligible ($32.5 million). Appendix D provides a breakdown of IO&P funding by U.N. entity. The majority of U.S. humanitarian assistance is provided to U.N. entities through the global humanitarian accounts, which fund voluntary contributions to U.N. entities. These contributions, which represent the bulk of U.S. funding to the United Nations, are sometimes viewed through a different lens because they do not fall under the umbrella of U.N. assessed contributions. Yet total U.S. funding to U.N. humanitarian-related activities is often equal to or greater than U.S. contributions to peacekeeping, the regular budget, and specialized agencies combined. Because the contributions are voluntary, funding to these organizations tends to fluctuate from year to year depending on U.S. priorities and global humanitarian needs ( Table 4 ). In FY2017, the last year for which comprehensive information is available, contributions to U.N. entities through these accounts totaled nearly $5.6 billion, compared to about $4.16 billion in FY2016 and $3.39 billion in FY2015. (FY2018 funding for U.N. entities has not yet been finalized.) Similar to previous Administrations, the FY2019 budget proposal does not outline how humanitarian funding might be distributed among U.N. entities or if it intends to reduce or expand U.S. contributions to such organizations. A detailed breakdown of global humanitarian-related funding by U.N. entity is provided in Appendix F . Members of Congress have debated the level and extent of U.S. funding to the United Nations since the United States first joined the organization in 1945. Over the decades, a number of recurring policy tools and issues have emerged, many of which may continue to be discussed in the 115 th Congress. For several decades, many U.S. policymakers, including some Members of Congress, have maintained that the U.S. assessments for the U.N. regular budget and U.N. peacekeeping operations are too high. In particular, some contend that current assessment levels for the regular budget result in a limited number of countries, particularly the United States, providing the bulk of funding while having what they view as minimal influence in the U.N. budget process. Some policymakers have expressed similar concerns about the U.S. peacekeeping assessment, which Congress has capped at 25%. They maintain that a cap on U.S. assessments plays an important role in keeping the current U.S. assessments from rising. On the other hand, some argue that the current assessment levels allow the United States to share peacekeeping, development, and humanitarian funding with other governments (often referred to as burden sharing) at a lower cost than if it were to act unilaterally. More broadly, they contend that current assessment levels reflect the U.S. commitment to the United Nations and allow the United States to pursue its policy priorities and maintain its influence in U.N. bodies. Some suggest that if the United States were to decrease its contributions to the United Nations, other countries with priorities at odds with the United States could step in and undermine U.S. interests. With these issues in mind, some Members of Congress may wish to monitor ongoing U.N. member states negotiations regarding the scale of assessments for the years 2019 through 2021. It is expected that the Assembly will adopt new regular budget and peacekeeping assessments in December 2018. The Trump Administration has stated that it will seek to reduce the U.S. peacekeeping assessment to the statutory cap of 25%. The last time there were significant changes to the U.N. scales of assessments was in 2000, when the U.S. regular budget assessment decreased from 25% to 22%, and the peacekeeping assessment decreased from over 30% to about 26% (it has since risen to 28.43%). Withholding funding from U.N. entities is one of the most common mechanisms by which Congress asserts or seeks to influence U.S. policy at the United Nations. In general, congressional withholdings fall into three categories: C aps on payment of U.S. assessments . Congress has at times limited U.S. payments to assessed budgets due to concerns that U.S. assessments were too high. In 1990s, for example, Congress capped the U.S. contribution to the U.N. regular budget at 22% and the U.N. peacekeeping assessment at 25%. F ull or partial withholdings from specific U.N. entities or activities . Over the years, and for a range of reasons, Congress has withheld or placed conditions on funding to selected U.N. entities or activities—some of which have required executive branch waivers or certifications to release funds ( Table 5 ). Co ngressional holds . Members of Congress have sometimes placed holds on U.N. funding through foreign affairs appropriations for policy reasons. Holds are generally requested by members of appropriations committees and, in many cases, little information is publicly available on the details of the hold. An additional category of withholding involves the executive branch. If Congress does not enact legislation that authorizes or appropriates funding to a specific U.N. entity, the Administration can unilaterally decide to withhold partial or full funding to such organizations, in some instances without being required to notify or consult with Congress. Congressional views on the role and effectiveness of U.S. withholdings vary. Some maintain that placing limitations or conditions on U.S. funding may weaken U.S. influence and standing within the organization, thereby undercutting the United States' ability to conduct diplomacy and make foreign policy decisions both in and out of the U.N. system. Some also argue that withholding U.S. assessed payments to the United Nations infringes on U.S. treaty obligations. On the other hand, some suggest that the United States should use its position as the largest U.N. financial contributor to push for the implementation of policies that are in the best interests of the United States. They contend that despite continued U.S. diplomatic and political pressures, U.S. foreign policy priorities are not adequately reflected in many U.N. bodies. The overall impact of U.S. withholdings on U.N. budget and operations depends on the origin of the program or entity's funding. For example, if an activity is funded by the U.N. regular budget and the United States withholds a proportionate share of its normal contributions, the cost of the program will most likely be covered, at least temporarily, by surplus regular budget funds. In such cases, a U.S. withholding would be largely symbolic and have little or no immediate impact on the program's operation or funding levels. On the other hand, if the United States withholds all or part of its assessed funding—or its voluntary contributions—from an entity funded primarily by member contributions, the impact of the U.S. withholding on the operations and budgets of such organizations could be significant—particularly for U.N. bodies for which the United States accounts for almost one-quarter of total funding. Some Members of Congress have demonstrated an ongoing interest in the accumulation of U.S. arrears to U.N. entities. Each U.N. body has its own payment timeline and system for defining and tracking arrears, which are generally outlined in the organization's constitution, statutes, or financial regulations. For instance, assessed contributions to the U.N. regular budget and U.N. peacekeeping operations are due and payable within 30 days of the receipt of notice from the U.N. Secretary-General. As of January 1 of the following calendar year, unpaid balances of such contributions are considered to be arrears. A consequence of accumulating arrears to the United Nations is the loss of voting rights in the General Assembly. Under Article 19 of the U.N. Charter, members who are in arrears "shall have no vote in the General Assembly if the amount of its arrears equals or exceeds the amount of the contributions due from it for the preceding two full years." In practice, the "amount of the contributions" refers to both assessed contributions to the U.N. regular budget and to U.N peacekeeping operations. Each U.N. specialized agency has its own rules and guidelines for nonpayment of arrears and the possible effects on membership. The causes of U.S. arrears often vary by U.N. entity, with total amounts fluctuating depending on the time of year. Congressional actions such as caps on assessments and withholdings from specific U.N. entities can play key roles in accumulating arrears. The aforementioned practice of deferred payments, which began under the Reagan Administration, also contributes. In the 1990s, the United States came close to losing its vote in the General Assembly under Article 19 due to substantial outstanding balances for the U.N. regular budget and U.N. peacekeeping. To prevent the loss of a vote, Congress and the Clinton Administration negotiated the "Helms-Biden Agreement" in 1999 that established conditions under which some U.S. arrears were paid. As of September 2017, the State Department reports that total estimated U.S. arrears to the U.N. regular budget are $347 million, while estimated arrears to U.N. peacekeeping budgets are $536 million. These arrears are the result of a combination of U.S. withholdings, deferred payments, and the U.N. peacekeeping cap. In some cases, the State Department plans to pay these arrears, but in other cases it does not. Congressional views on the payment of U.S. arrears are mixed. Some Members argue that they should be fully paid, while others do not recognize U.S. outstanding balances as arrears and claim the United States is under no obligation to pay them. Recognizing the complexity of tracking U.N. funding, over the years Congress has enacted several executive branch reporting requirements to help determine the full level and extent of U.S. contributions. The first of these reports, United States Contributions to International Organizations, has been published annually since 1952; in FY2016 Congress expanded its requirements to include information on the source of funds—including federal agency and account—and a description of the purpose of such funds disbursed in the previous year to international organizations in which the United States is a participant. During the past decade, Congress has periodically enacted additional reporting requirements. From FY2007 to FY2010, defense authorization legislation required that the Office of Management and Budget (OMB) submit an annual report to Congress listing all assessed and voluntary contributions to the United Nations and its related bodies. More recently, the Department of State Authorities Act, FY2017 ( P.L. 114-323 ) directed that OMB annually submit to Congress a report on all U.S. assessed and voluntary contributions to the United Nations with a value greater than $100,000, including in-kind services, during the previous fiscal year. Some of these more recent reporting requirements are similar to, and overlap with, previously enacted requirements. In certain cases, the executive branch has combined multiple requirements into one report. A key challenge to compiling U.N. funding-related data is one of self-reporting. According to the State Department, each participating agency is responsible for the completeness and accuracy of the information provided in the reports, and not all executive branch agencies provide the requested data. The agencies charged with compiling the reports, such as the State Department or OMB, often lack the authority to require other agencies to respond accurately or within a given timeframe, if at all. Consequently, some reporting requirements are incomplete and may not illustrate the full scope of U.S contributions. Since its establishment, the United Nations has evolved as various international stakeholders seek ways to improve the efficiency and effectiveness of the U.N. system through reform. Some Members of Congress have demonstrated a continued interest in U.N. reform and over the years have sought to link U.S. funding to specific reform benchmarks. In the 1980s and 1990s, for example, Congress enacted legislation tying U.S. funding to U.N. reform and U.N. regular budget policies that favored the United States, including caps on the U.S. assessments rates, changes to U.N. budget processes, and strengthening U.N. internal oversight. More recently, Congress has enacted legislation conditioning U.S. funding on the implementation of management reforms that aim to improve transparency and accountability (see text box ) and withholding funding to specific U.N. entities, such as the Human Rights Council. Congress has also demonstrated an increased interest in U.N. reforms related to sexual exploitation and abuse (SEA) by U.N. peacekeepers; legislation in the 115 th Congress requires that the United States withhold assistance from "any unit of the security forces of a foreign country" if the Secretary of State determines such unit has engaged in SEA while serving in a U.N. peacekeeping operation. More broadly, some Members have introduced legislation requiring a government-wide review of U.S. multilateral aid. The explanatory statement to the Consolidated Appropriations Act, 2018, requires the Secretary of State to provide Congress with a report that includes a description of current tools, methods, and resources to assess the value of, and prioritize contributions to, international organizations and other multilateral entities, as well as to provide related recommendations. Supporters of linking U.S. funding to U.N. reform contend that the United States should use its position as the largest U.N. financial contributor to push for the implementation of policies that lead to comprehensive reform. They note that despite diplomatic and political pressures from many countries, the United Nations has been slow to implement substantive reform. They believe that tying U.S. funding to reform may motivate countries to find common ground on otherwise divisive issues. On the other hand, opponents argue that linking U.S. funding to U.N. reform might not be effective and could ultimately weaken U.S. influence at the United Nations. In particular, some maintain that U.N. reform legislation proposals may be unrealistic because the scope and depth of reforms required by the legislation cannot be adequately achieved in the proposed timeframes. Some also contend that the United States can obtain its U.N. reform objectives through other means, including collaborating with like-minded members and working with the U.N. Secretary-General on common reform priorities. Policymakers have observed that countries that receive U.S. foreign aid sometimes vote against U.S. foreign policy or national security interests in U.N. bodies such as the Security Council and General Assembly. On occasion, the United States has periodically debated linking U.S. foreign assistance to the U.N. voting records of potential aid recipients. Supporters maintain that doing so could increase member support for U.S. policy priorities in U.N. bodies. The Reagan Administration strongly supported such a policy; then-U.N. Ambassador Jeanne Kirkpatrick stated in a 1983 congressional hearing that the United States must "communicate to nations that their votes, their attitudes and their actions inside the U.N. system inevitably must have consequences for their relations with the United States outside the U.N. system." Recognizing these concerns, in 1984 Congress required the State Department to submit an annual report to Congress, Voting Practices in the United Nations, which tracks member voting records on U.N. resolutions important to the United States. Over the years, some Members of Congress have also periodically introduced, but not enacted, legislation requiring reductions in foreign aid to countries that do not consistently vote with the United States. Opponents of these efforts contend that reducing funding to countries based on U.N. voting records could undermine the overall effectiveness of U.S. foreign assistance and, depending on the issue being considered in U.N. bodies, ultimately have little impact on how countries vote. Some have also questioned the criteria the State Department would use to eliminate or decrease aid, noting that many U.S. foreign aid priorities are based on a combination of need and political considerations that may not always align with how countries vote in the United Nations. They further contend that withholding aid in this manner might punish the citizens of countries who often have the greatest need and no control over the foreign policy decisions of their leaders. In the past year, President Trump and Ambassador Haley have expressed support for linking U.S. foreign aid to U.N. votes; prospects for implementation, however, are unclear. Congress is ultimately responsible for appropriating foreign assistance to specific countries, and the Trump Administration's FY2019 budget did not propose foreign aid reductions based on U.N. votes. Many congressional debates regarding U.N. funding occur against the backdrop of competing foreign and domestic funding priorities and broad questions about the role of the United Nations in U.S. national security and foreign policy. The emergence of President Trump's "America First" position raises questions about the future of U.S. participation in and funding of the United Nations. In the near term, Members of the 115 th Congress might consider the following issues: How, if at all, the President's FY2019 budget proposal aligns with congressional perspectives on U.N. funding. What role and actions, if any, Congress might take in the absence of Administration support for some U.N. activities. The possible impacts of current and potential U.S. financial withholding on (1) U.S. influence in U.N. bodies, and (2) the operations and effectiveness of U.N. activities—particularly in light of continued accumulation of U.S. peacekeeping arrears and the Administration's proposed funding reductions for certain U.N. bodies. In the longer term, some Members might consider the following U.N. funding issues in the context of the changing multilateral and global landscape. The benefits and drawbacks of U.S. funding of the United Nations—including areas where the United States can (1) reduce funding while increasing efficiency and accountability or (2) achieve the most "bang for its buck." Steps Congress can take to ensure that U.S. contributions to the U.N. system are used as effectively as possible. The domestic and foreign policy implications, if any, of reduced U.S. participation in and funding of the United Nations, including the possible impact of other countries stepping into the funding and leadership role traditionally held by the United States. How the United States can further its U.N. reform agenda, and to what extent, if any, such efforts could be linked to U.S. funding. The advantages and disadvantages of multilateral and bilateral U.S. assistance, including the comparative advantage, if any, the United Nations might have over other multilateral organizations, and how the United States might maximize this advantage. Appendix A. Organizational Chart of the U.N. System Appendix B. Contributions to International Organizations (CIO) Account by U.N. Entity The following table lists CIO account funding by U.N. and U.N.-affiliated entities since FY2015, including amounts appropriated by Congress and U.S. assessment levels. FY2018 funding levels for individual U.N. bodies are not yet available. Appendix C. Contributions for International Peacekeeping Activities (CIPA) Account by U.N. Peacekeeping Operation The following table lists CIPA account funding by peacekeeping operation since FY2015, including amounts appropriated by Congress. FY2018 funding levels for individual peacekeeping missions have not yet been finalized. Appendix D. International Organizations and Programs (IO&P) Account by U.N. Entity The following table lists U.S. contributions to U.N. entities through the IO&P account since FY2015. Appendix E. Timeline of U.S. Peacekeeping Assessment Cap The following table outlines changes to the U.S. peacekeeping assessment and enacted U.S. peacekeeping cap since FY1994, including related legislation. Appendix F. Global Humanitarian Accounts by U.N. Entity Table F-1 provides an overview of top U.S. voluntary contributions to U.N. humanitarian-related activities through the global humanitarian accounts since FY2015. Contributions for each account are appropriated by Congress, with the executive branch allocating funding to specific U.N. entities and activities based on humanitarian needs and U.S. foreign policy priorities. Some U.N. entities are funded through both State and USAID accounts, while others are only funded through specific agencies or agency accounts. Funding for U.N. entities in FY2018 has not been finalized. Appendix G. Selected Legislation: U.S. Funding and U.N. Reform The following sections highlight selected reform legislation from 1986 to the present that ties U.S. funding to U.N. reform and notes any subsequent changes to internal U.N. policy. Kassebaum-Solomon Amendment (1986-1987) In the mid-1980s, some Members of Congress expressed concern that U.S. influence over the U.N. budget was not proportionate to its rate of assessment. In 1986 Congress passed legislation, popularly known as the "Kassebaum-Solomon amendment," which required that the U.S. assessed contribution to the U.N. regular budget be reduced to 20% unless the United Nations gave major U.N. financial contributors a greater say in the budget process. Subsequently, in 1986 the General Assembly adopted a new budget and planning process that incorporated consensus-based budgeting as a decisionmaking mechanism, thus giving U.N. members with higher assessment levels a potentially greater voice in the budget process. U.N. Office of Internal Oversight Services (1993) In the early 1990s, some Members of Congress and the Administration were concerned with the apparent lack of oversight and accountability within the U.N. system. In 1993, as part of the FY1994 State Department Appropriations Act, Congress directed that 10% of U.S. assessed contributions to the U.N. regular budget be withheld until the Secretary of State certified to Congress that "the United Nations has established an independent office with responsibilities and powers substantially similar to offices of Inspectors General Act of 1978. On July 29, 1994, the U.N. General Assembly established the Office of Internal Oversight Services (OIOS) which reports directly to the Secretary-General and provides "internal auditing, investigation, inspection, programme monitoring, evaluation and consulting services to all U.N. activities under the Secretary-General's authority." Helms-Biden Agreement (1999) In the late 1990s, Congress and the Administration negotiated and agreed to legislation that would further U.S. reform policy at the United Nations. The Helms-Biden bill authorized payment of some U.S. arrears if specific reform benchmarks were met and certified to Congress by the Secretary of State. Under the terms of Helms-Biden, the United States agreed to (1) pay $819 million in arrearages over fiscal years 1998, 1999, and 2000; and (2) forgive $107 million owed to the United States by the United Nations in peacekeeping costs if the United Nations applied the $107 million to U.S. peacekeeping arrears. For arrearage payments to occur Congress required that the U.S. assessment for contributions to the U.N. regular budget be reduced from 25% to 22% and that the peacekeeping contribution be reduced from 30% to 25%. In December 2000, the U.N. General Assembly reduced the regular budget assessment level from 25% to 22%, and the peacekeeping share from approximately 30.4% to 28%. In subsequent years, the U.S. peacekeeping assessment continued to fluctuate and is currently 28.43%.

Summary: Members of Congress are responsible for authorizing and appropriating U.S. funding to the United Nations (U.N.) system. Over the years, congressional interest in U.N. funding has largely focused on three key questions: What are appropriate levels of U.S. funding to U.N. entities? Are U.S. contributions used as efficiently and effectively as possible? How, if at all, should the United States leverage U.S. contributions to achieve its policy priorities in U.N. bodies? U.N. System Funding The U.N. system is made up of interconnected entities including specialized agencies, funds and programs, peacekeeping operations, and the U.N. organization itself. The U.N. Charter requires each U.N. member to contribute to the expenses of the organization. U.N. bodies are funded by a combination of assessed and voluntary contributions. Assessed contributions are required dues shared among U.N. member states to pay for the expenses of the organization. The U.N. regular budget, peacekeeping operations, and specialized agencies are funded mainly by assessed contributions. Voluntary contributions fund U.N. funds, programs, and offices. The budgets for many of these bodies may fluctuate annually depending on contribution levels. Organizations such as the U.N. Children's Fund (UNICEF) and U.N. Development Program (UNDP) are financed mainly by voluntary contributions. U.S. Contributions The United States is the largest financial contributor to the U.N. system, providing 22% of the U.N. regular budget and 28.43% of U.N. peacekeeping budgets. In FY2017, it contributed more than $8.5 billion to U.N. entities through the State, Foreign Operations, and Related Programs (SFOPS) appropriations act. Congress usually authorizes the majority of U.S. contributions to the U.N. system as part of Foreign Relations Authorization Acts, with appropriations provided to the Department of State and U.S. Agency for International Development (USAID) to meet obligations. When authorization bills are not enacted, Congress has waived the authorization requirements and appropriated funds through annual SFOPS appropriations acts. The Trump Administration's FY2018 and FY2019 budgets proposed significant reductions in U.N. funding. Selected Policy Issues Since the United Nations was established in 1945, Members of Congress have considered a number of ongoing issues related to U.N. funding: U.S. assessment levels. Some policymakers are concerned that current assessment levels result in the United States providing the bulk of funding to U.N. entities, particularly the U.N. regular budget, while having minimal influence on the organization's budget processes. Some are concerned that the U.S. peacekeeping assessment of 28.43%, which Congress capped at 25%, is too high. Others argue that the U.S. assessment reflects its commitment to the United Nations, affirms U.S. global leadership, and encourages other countries to fund the organization. U.S. withholdings. Over the years, Congress has withheld full or partial funding from selected U.N. bodies and activities. Some Members of Congress have debated the effectiveness of such withholdings in furthering U.S. interests in U.N. bodies, as well as the potential impact on U.N. operations. U.S. arrears. For the past several decades, the United States has accumulated arrears for some U.N. entities and activities, including U.N. peacekeeping. Some Members continue to discuss the impact of these arrears and whether they should be paid. U.S. funding and U.N. reform. Congress has enacted legislation linking U.S. funding to specific U.N. reform benchmarks. Some policymakers oppose such actions due to concerns that they may interfere with U.S. influence and ability to conduct diplomacy in U.N. bodies. Others suggest that the United States should use its position as the largest financial contributor to push for certain U.N. reforms. Tracking U.S. contributions. The manner in which the United States provides funding to the U.N. system is complex and often difficult to track in a timely and accurate manner. Congress has enacted several U.N. funding reporting requirements over the years. While some of these efforts have provided useful snapshots of U.S. funding during particular time periods or to select U.N. bodies, for a number of reasons few have comprehensively captured the full scope of U.S. funding to the U.N. system. This report will be updated as events warrant. For a brief overview of U.N. funding, see CRS In Focus IF10354, United Nations Issues: U.S. Funding to the U.N. System.