"This report summarizes what is known from open sources about the North Korean nuclear weapons program including weapons-usable fissile material and warhead estimates and assesses current developments in verifying dismantlement of North Korea's nuclear facilities as agreed in the Six-Party Talks. The Six-Party Talks include the United States, South Korea, Japan, China, Russia, and North Korea, and were begun in August 2003 to attempt to resolve the current crisis over North Korean nuclear weapons... Much still remains to be confirmed regarding North Korea's nuclear weapons production capabilities and delivery systems, particularly regarding uranium enrichment. Although U.S. officials confronted the North Koreans in 2002 with intelligence that reportedly proved that Pyongyang was pursuing a uranium enrichment program, U.S. intelligence officials have said they do not know where the uranium program is based and have over time shown less confidence about what the scope of the program might be. Further, although seismographs registered the October 9, 2006, detonation and environmental sampling confirmed radioactivity, uncertainty about the weapon's design and sophistication remains. Additional transparency on fissile material stocks and programs, including the uranium enrichment program, may contribute to a better picture of North Korean nuclear weapons capabilities. This report will be updated as events warrant."
CRS Report for Congress, RL34256