US relations with North Korea have fluctuated between cooperation and hostility over the decades. Key events included the US occupation of South Korea after World War 2 and the formation of North Korea, as well as tensions over North Korea's nuclear program under George W. Bush. Beginning in 2003, six-party talks involving the US, North Korea, South Korea, China, Japan, and Russia aimed to negotiate North Korea's denuclearization, resulting in some agreements, though also further strains such as North Korea's nuclear tests. The document outlines the history of interactions between the two countries.