 North Korea has been suspected of maintaining a clandestine nuclear weapons development program since the early 1980s, when it constructed a plutonium-producing Magnox nuclear reactor at Yongbyon.Various diplomatic means have been used by the international community to attempt to limit North Korea's nuclear program to peaceful power generation and to encourage North Korea to participate in international treaties.In May 1992, the International Atomic Energy Agency's (IAEA) first inspection in North Korea uncovered discrepancies suggesting that the country had reprocessed more plutonium than declared.