Debt-for-nature initiatives were conceived to address the rapid loss of resources and biodiversity in developing countries that were heavily indebted to foreign creditors. Conservationists had noted that the pressure to pay off foreign debts in hard currency was leading to increased levels of natural resource exports (i.e., timber, cattle, minerals, and agricultural products) at the expense of the environment. In many cases, indebted developing countries had difficulty meeting their hard currency debt obligations and defaulted. Reducing foreign debt and allowing for portions of it to be paid with local currency while increasing funds for the environment was thought to improve environmental conditions in developing countries and had the advantage of relieving the debtor country's difficulties in procuring sufficient hard currency to pay off its debts. Money generated from debt-for-nature transactions has been used to fund a variety of projects, ranging from national park protection in Costa Rica to supporting ecotourism in Ghana and conserving tropical forests in Bangladesh. Since 1993, there has been a declining trend in the number of debt-for-nature transactions involving official (public) and private funds. Accounting changes requiring new appropriations to support official (public) debt transactions in creditor countries such as the United States, and a higher price of commercial debt on secondary markets, are two reasons suggested for the decline of debt-for-nature transactions. While Congress has periodically authorized U.S. participation in three-party debt-for-nature transactions and has supported two bilateral debt-for-nature initiatives, appropriations to support these types of efforts have generally diminished over the years. Early debt-for-nature legislation concentrated on understanding and promoting third-party debt-for-nature transactions (see Appendix for legislation summaries and United States Code citations). Congress in 1989 directed the Secretary of the Treasury to ask the U.S. Executive Director of the World Bank to develop a pilot debt-for-nature program and other ways of reducing debt owed by foreign countries while generating funds for the environment. A subsequent law, the International Development and Finance Act of 1989, authorized the U.S. Agency for International Development (USAID) to make grants to nongovernmental organizations (NGOs) to purchase debt in three-party transactions. Official (public) P.L. 480 debt owed to the United States by eligible Latin American countries was authorized to be reduced by the 1990 farm bill ( P.L. 101-624 ; 7 U.S.C. 1738b). The 102 nd Congress authorized debt reduction for foreign assistance loans made by USAID ( P.L. 102-549 ; 22 U.S.C. 2430 and 2421), the Export-Import Bank (Ex-Im Bank; P.L. 102-429 ; 12 U.S.C. 635i-6), and the Commodity Credit Corporation (CCC; P.L. 102-549 ; 22 U.S.C. 2430 and 2421). Together, the P.L. 480, USAID, Ex-Im, and CCC debt-reduction authorizations were undertaken as part of President George H. W. Bush's Enterprise for the Americas Initiative. In 1996, USAID was further authorized by Congress to conduct swaps, buybacks, and cancellations of debt owed to the United States by eligible Latin American and Caribbean countries ( P.L. 104-107 ). In 1998, the Tropical Forest Conservation Act (TFCA; P.L. 105-214 ; 22 U.S.C. 2431) was passed, allowing debt swaps, buybacks, and restructuring to generate funds for tropical forest conservation worldwide. Funding for the TFCA was reauthorized by Congress in 2004 ( P.L. 108-323 ). In the 115 th Congress, S. 1023 would authorize appropriations for the TFCA of $20.0 million annually from FY2018 to FY2021. The bill also would expand the TFCA to include coral reefs and coral reef ecosystems. Further, the bill would allow concessional debt incurred before the date of enactment of the bill to be eligible for debt-for-nature transactions. Under current law, eligible concessional debt must be incurred before 1998. Three-party debt-for-nature transactions, involving nongovernmental organizations such as The Nature Conservancy and Conservation International, were the first debt-for-nature agreements to be formed. In a three-party swap, a conservation group purchases a hard currency debt owed to commercial banks on the secondary market or in some cases a public (official) debt owed to a creditor government at a discounted rate compared to the face value of the debt, and then renegotiates the debt obligation with the debtor country. The debt is generally sold back to the debtor country for more than it was purchased for by the NGO, yet less than what it was on the secondary market. The proceeds generated from the renegotiated debt, to be repaid in local currency, are typically put into a fund that often allocates grants to local environmental organizations for conservation projects (see Figure 1 ). In these cases, the fund is administered by the conservation organization, representatives from local environmental groups, and the debtor government. Money to buy the debt initially may come from the nongovernmental organization, governments, banks, or other private organizations. In 1989, Congress authorized the United States Agency for International Development (USAID) to provide assistance to nongovernmental organizations to purchase the commercial debt of foreign countries as part of debt-for-nature agreements ( P.L. 101-240 ; 22 U.S.C. 2282-2286). Several nongovernmental organizations participated in debt-for-nature transactions with financial assistance from USAID; however, specific information on funds given by USAID to support three-party debt-for-nature transactions was not available. While debt initiatives conducted with three-party transactions are numerous, they have resulted in less reduction in total debt than the debts swapped under bilateral agreements (government-to-government), and slightly less in conservation funds generated. In total, approximately $200 million in debt (face value) has been reduced, restructured, or swapped using this mechanism, generating approximately $167 million in local currency for conservation purposes (see Table 1 ). Bilateral debt transactions are conducted with official (public) funds directly between the creditor and debtor governments. The creditor government determines the criteria for eligibility, which usually involve the existence of certain financial and political conditions in the debtor country. Debt agreements are usually cancelled and then restructured to extend payback periods, or in some cases, debt is bought back by the debtor country for a discounted price. Money for the environment can be generated through interest payments from the debtor country if the debt is restructured, or from a percentage of the buyback price. Multilateral debt-for-nature agreements have also been conducted between more than one creditor country and a debtor country (see Table 2 ). The model for bilateral debt-for-nature agreements conducted by the United States was first defined in 1990 by the Enterprise for the Americas Initiative (EAI; Title 15, Section 1512 of the Food, Agriculture Conservation and Trade Act of 1990, "1990 farm bill," P.L. 101-624 ; 7 U.S.C. 1738) and has since been expanded numerous times (see Appendix ). It was last amended by the Tropical Forest Conservation Act (TFCA) in 1998 ( P.L. 105-214 ; 22 U.S.C. 2431). The EAI legislation authorizes the sale, reduction, cancellation, and country buyback of eligible debt of Latin American and Caribbean countries that meet certain criteria. The debt authorized to be treated include the following types: P.L. 480 debt ( P.L. 101-624 ; 7 U.S.C. 1738m, p-r, etc.) AID debt ( P.L. 102-549 ; 22 U.S.C. 2430 and 2421) CCC debt ( P.L. 102-549 ; 22 U.S.C. 2430 and 2421) Exim debt ( P.L. 102-429 ; 12 U.S.C. 635i-6) Debtor countries must meet certain political and macroeconomic criteria in order to be eligible. Eligible countries are required to (1) have a democratically elected government, (2) not support terrorism, (3) not fail to cooperate with the United States on drug control, and (4) not engage in gross violations of human rights. From an economic perspective, eligible countries are required to have (1) an International Bank for Reconstruction and Development (IBRD) or International Development Association (IDA) structural or sectoral adjustment loan or its equivalent, (2) a macroeconomic agreement with the International Monetary Fund or equivalent, and (3) instituted investment reforms, as evidenced by a bilateral investment treaty with the United States, an investment sector loan, or progress towards implementing an open investment regime. Each country that participates in the EAI must enter into an Americas Framework Agreement with the United States to establish an Americas Trust Fund and create enforcement mechanisms to insure payments into the fund and prompt disbursements out of the fund. Funds can be used to support environmental, natural resource, health protection, and child development programs within the debtor country. Debt swaps, buybacks, and restructuring are three mechanisms authorized to conduct debt-for-nature transactions under the EAI. Seven of the eight countries that have participated in debt-for-nature transactions under the EAI used the debt-restructuring mechanism to generate environmental funds (see Table 3 ); only Peru took advantage of the debt buyback option.