Since then, there have been no formal relations between Washington and Pyongyang, which found itself firmly on the communist side of the Cold War. After the collapse of the Soviet Union in the early 1990s, however, then-President Bill Clinton demanded North Korea allow entry to inspectors of the U.N.'s International Atomic Energy Agency, who were refused in 1994, a violation of the deal that halted the Korean War. While carefully balancing escalation and diplomacy, Clinton managed to form the Agreed Framework between the pair, giving heavy oil and light-water reactors to North Korea in exchange for a nuclear freeze, and the Four Party Talks involving Japan and China in 1996.
Diplomacy persisted under the administration of former President George W. Bush, despite him placing North Korea, along with Iraq and Iran, on his "Axis of Evil." Allegations that North Korea had secretly continued enriching uranium led nations supporting the Clinton-era initiative to supply heavy oil to North Korea to cease shipments in October 2002. In response, North Korea withdrew from the Non-Proliferation Treaty, expelling international monitors and kickstarting nuclear production in early 2003. Later that year, Bush brought North Korea to the table again, along with China, Russia, Japan and South Korea, for the Six-Party Talks.
These talks were the last major dialogue between the U.S. and North Korea to date and, although North Korea committed in 2005 to "abandoning all nuclear weapons and existing nuclear programs," negotiations began to unravel with dueling accusations of violations to the agreement. North Korea then tested its first nuclear weapon in 2006. In an effort to restart talks, the U.S. agreed to remove North Korea from the State Sponsors of Terrorism list later that year (Trump returned North Korea to the list last month) and, in 2008, North Korea destroyed one of its cooling towers, used for nuclear production. Sky more