This report provides background information on the negotiations over North Korea's nuclear weapons program that began in the early 1990s under the Clinton Administration. As US policy toward Pyongyang evolved through the George W. Bush presidency and into the Obama Administration, the negotiations moved from mostly bilateral to the multilateral Six-Party Talks. Although the negotiations have reached some key agreements, major problems with the implementation have persisted. With talks suspended since 2009, concern about proliferation to other actors has grown.