 In recent years relations have been largely defined by North Korea's nuclear program – six tests of nuclear weapons, its development of long-range missiles capable of striking targets thousands of miles away, and its ongoing threats to strike the United States and South Korea with nuclear weapons and conventional forces.During his presidency, George W. Bush referred to North Korea as part of "the Axis of Evil" because of the threat of its nuclear capabilities.Recently, North Korea and the United States of America have started some formal diplomacy after the first Trump-Kim Summit in 2018.