On October 9, 2006, North Korea (formally the Democratic People's Republic of Korea) announced it conducted a nuclear test. After several days of evaluation, U.S. authorities confirmed that the underground explosion was nuclear, but that the test produced a low yield of less than one kiloton. The test followed a pattern of North Korean provocations and escalations, including the launch of several short-, medium-, and long-range missiles in July 2006. Since the United States threatened financial sanctions on banks that do business with North Korea in September 2005, Pyongyang had boycotted the Six-Party Talks (with South Korea, Japan, China, and Russia), the multilateral forum dedicated to eliminating North Korea's nuclear weapons program. Since the end of the Agreed Framework in 2002, experts estimate that North Korea may have added about six to eight more weapons' worth of plutonium to a fissile material stockpile. President Bush and other U.S. officials immediately condemned the test and called for a swift response from the United Nations Security Council (UNSC). At the U.N., the United States pushed for punitive sanctions and drafted a resolution that was eventually unanimously adopted. In a hastily-arranged trip to the region, Secretary of State Rice reiterated the U.S. security commitment to South Korea and Japan and urged China and South Korea to implement key measures of the U.N. resolution. North Korean officials reportedly told Russian officials the test of the explosive device would have a range of yield between 5 and 15 kilotons; another report suggests that North Korea told Chinese officials they planned to carry out a 4-kiloton test. Seismic information available from the Korea Institute of Geoscience and Mineral Resources in South Korea indicates that an explosion equivalent to an earthquake measuring a 3.58 magnitude occurred at 10:35 a.m. on October 9 in the vicinity of Musudan-ri, North Hamgyong Province. Most experts have correlated the size of the seismic disturbance with a sub-kiloton explosion, raising doubts about the effectiveness of the North Korean nuclear weapons design. On October 16, 2006, the U.S. Director of National Intelligence issued a statement confirming that a nuclear test was conducted, with a yield under 1 kiloton, in the vicinity of P'unggye. Several experts have suggested that the nuclear test might have fallen short of the anticipated yield because of imprecise manufacturing. According to one account, U.S. intelligence estimates that the blast was in the range of 200 tons of TNT, or 0.2 kt. By comparison, a simple plutonium implosion device normally would produce a larger blast, perhaps 5 to 20 kilotons. The first nuclear tests conducted by other states have ranged from 9 kt (Pakistan) to 60 kt, but tests by the United States, China, Britain and Russia were in the 20kt-range. On December 8, 2006, President Bush officially determined that North Korea had detonated a nuclear explosive device, as required by section 102(b)(1) of the Arms Export Control Act (P.L. 90-629). On December 11, 2006, Chinese officials announced that the multilateral negotiations would resume on December 18, 2006. In the weeks preceding, U.S. negotiators had reportedly offered some specific details on what assistance North Korea could expect (although those details were not made public). The United States further agreed to put the financial sanctions on the agenda, while North Korea dropped its demand that the sanctions be lifted as a precondition for the talks. For more details on the Talks, see CRS Report RL33590, North Korea ' s Nuclear Weapons Development and Diplomacy , by [author name scrubbed]. This report complements several other existing CRS reports. For more information on North Korea's nuclear weapons program history, development, and current status, see CRS Report RL33590, North Korea ' s Nuclear Weapons Development and Diplomacy , by [author name scrubbed] and CRS Report RS21391, North Korea ' s Nuclear Weapons: Latest Developments , by [author name scrubbed]. For further details on sanctions, see CRS Report RL31696, North Korea: Economic Sanctions , by [author name scrubbed]; on missiles, see CRS Report RS21473, North Korean Ballistic Missile Threat to the United States , by [author name scrubbed]; on counterfeiting issues, see CRS Report RL33324, North Korean Counterfeiting of U.S. Currency , by [author name scrubbed]. Further reports are also available on the North Korean economy, U.S. and international assistance to North Korea, general U.S.-Korean relations, and chronologies of events related to North Korea. In the 109 th Congress, Congress became more involved in, and at times critical of, U.S. policy toward North Korea. In late September and early October 2006, Congress enacted two pieces of legislation on North Korea. The John Warner National Defense Authorization Act for FY2007 ( H.R. 5122 / P.L. 109-364 ), requires the President to appoint a Policy Coordinator for North Korea within 60 days of enactment and report to the President and Congress within 90 days on recommendations. It also requires the executive branch to report to Congress every 180 days in fiscal years 2007 and 2008 on the status of North Korea's nuclear and missile programs. The North Korea Nonproliferation Act of 2006 ( P.L. 109-353 ) adds North Korea to the Iran-Syria Nonproliferation Act ( P.L. 106-178 ; P.L. 109-112 ), authorizing sanctions on third party "persons" for weapons-of-mass-destruction-related transfers to and from North Korea. In particular, this could affect North Korea's missile trade. In response to the test, the UNSC unanimously supported a U.S.-drafted resolution, Res. 1718, that calls the test "a clear threat to international peace and security," bans trade in heavy weapons and luxury goods, authorizes countries to inspect cargo bound to and from North Korea to look for weapons of mass destruction or related materials, and requests that countries freeze funds related to North Korea's non-conventional weapons programs. It also calls on North Korea to refrain from conducting additional nuclear or ballistic missile tests, rejoin the Nuclear Nonproliferation Treaty (NPT), suspend its ballistic missile program and eventually abandon its nuclear weapons in a complete, verifiable, and irreversible manner. Compared to the original U.S. draft, the final resolution was weakened in several key areas at the insistence of China and Russia, both permanent members of the UNSC. China insisted that the language request, but not require , that countries inspect cargo going into and out of North Korea and that the resolution explicitly rule out the use of military force. A more robust military embargo was scaled back to include only heavy military equipment such as tanks and missiles. Following passage of Res. 1718, North Korea declared it considered the imposition of sanctions an act of war. It is unclear how the sanctions will affect North Korea, already among the most isolated and poor countries in the world with limited global trade. Many experts argue that sanctions are ineffective at changing the fundamental political goals of governments. In addition, Res. 1718 bans trade in certain items, rather than a complete embargo, which some say lends itself to circumvention. The sanction regime depends heavily on individual states' compliance with the guidelines. For example, each state can determine what items are considered "luxury goods." China has sought to balance its wish to send a stern message to Pyongyang with its determination to avoid sparking a destabilizing military conflict. Beijing has made clear its overriding goal of preventing the collapse of the North Korean regime, which it fears would interrupt its surging economic development and bring thousands of North Korean refugees across the border into China. Analysts point out that China is also motivated by a desire to keep North Korea as a "buffer state" between it and the U.S. troops stationed in South Korea. Chinese officials maintain that the UNSC resolution should "create conditions conducive to the peaceful resolution of this issue through dialogue and negotiation." According to press reports, after the passage of the resolution, Chinese officials began inspecting trucks bound for North Korea more closely. Questions have arisen on whether China will enforce the sanctions regime on air or ship trade, and Beijing said it would not stop North Korean-bound ships to conduct inspections for illegal weapons and missiles as the resolution requests. Chinese officials insist that they are implementing the U.N. resolution, but that "normal trade" with North Korea should not be disrupted. Economists argue that the only definitively effective punishment on North Korea would be the suspension of energy aid from China; China reportedly supplies about 70% of North Korea's fuel. After the test, reports citing Chinese trade statistics showed a marked decline of oil exports to North Korea in September, prompting speculation that Beijing may have been punishing Pyongyang for the July missile tests and/or warning it not to test a nuclear device as threatened. Chinese officials subsequently denied any cutoff, however, and customs data showed a resumption of crude oil to North Korea in October. Some analysts suggest that Beijing could be employing a more subtle form of pressure by sending fewer refined oil products, but there is no overwhelming evidence that China has tried to punish North Korea by restricting energy trade. The South Korean government vowed to support the UNSC resolution and called for Pyongyang to return to the Six-Party Talks, but also said it will not suspend cooperation with North Korea on the Kaesong Industrial Park (where South Korean firms employ North Korean workers at a complex in the North, about one hour from Seoul) and the Mt. Kumgang tourism site.