— 1994: Under agreement with US, North Korea pledges to freeze and eventually dismantle its nuclear weapons program in exchange for help building two safer power-producing nuclear reactors.
— Aug. 31, 1998: North Korea fires suspected missile over Japan and into the Pacific Ocean, calling it a satellite.
— Sept. 13, 1999: North pledges to freeze long-range missile tests.
— July 2001: U.S. State Department reports North Korea is developing long-range missile.
— December 2001: President George W Bush warns Iraq and North Korea will be "held accountable" if they develop weapons of mass destruction.
— Jan. 10, 2003: North Korea announces withdrawal from Nuclear Nonproliferation Treaty.
— August 2003: North Korea joins first round of six-nation nuclear talks in Beijing with China, U.S. Japan, Russia and South Korea.
— July 5, 2006: North Korea launches seven missiles into waters between the Korean peninsula and Japan, including a medium-range Taepodong-2.
— July 15, 2006: UN Security Council adopts Resolution 1695 demanding North Korea halt missile program.
— Oct. 9, 2006: North Korea conducts underground nuclear test blast after citing "extreme threat of a nuclear war" from U.S.
— Oct. 15, 2006: UN Security Council adopts Resolution 1718 condemning test, imposing sanctions and banning North Korea from all activities related to its nuclear weapons program.
— Feb. 13, 2007: North Korea agrees to disable its main nuclear facilities in return for energy aid and other benefits.
— July 14, 2007: North Korea shuts down main Yongbyon reactor, later starts disabling it.
— June 27, 2008: North Korea destroys cooling tower at Yongbyon.
— Sept. 19, 2008: North Korea says it is restoring nuclear facilities at Yongbyon.
— Oct. 11, 2008: U.S. removes North Korea from a list of states that sponsor terrorism.
— Feb. 15, 2009: North Korea claims it has the right to "space development."
— Feb. 23: South Korea says North Korea has a new type of ballistic missile capable of reaching northern Australia and Guam.
— April 5: North Korea launches long-range rocket from its base on the country's northeast coast.
— April 13: UN Security Council condemns launch.
— April 14: North Korea announces withdrawal from disarmament talks and says it will restore partly disabled nuclear facilities.
— April 25: North Korea announces start of reprocessing of spent fuel rods from its nuclear plant. A UN Security Council committee approves new sanctions on three major North Korean companies in response to the rocket launch.
— April 29: North Korea threatens to conduct nuclear and intercontinental ballistic missile tests unless the UN Security Council apologizes for criticizing its long-range rocket launch.
— May 7-12: Special U.S. envoy on North Korea visits Asia, says Washington is ready for direct talks with Pyongyang.
— May 8: North Korea dismisses talks with U.S. as useless, citing Washington's "hostile policy".
— May 25: North Korea announces it successfully conducted a nuclear test.
Sources: South Korean government, AP reports.Reuse content