-- 1993: North Korea shocks world by saying it will quit Nuclear Nonproliferation Treaty, later suspends its withdrawal.

-- 1994: North Korea, United States sign agreement in Geneva, North pledges to freeze, eventually dismantle, nuclear weapons program in exchange for help building two power-producing nuclear reactors.

-- September 17, 1999: US President Bill Clinton agrees to first major easing of economic sanctions against North Korea since Korean War's end in 1953.

-- July 2000: North Korea said it would restart nuclear program if Washington does not compensate for loss of electricity due to delays in building nuclear power plants.

-- June 2001: North Korea warns it will reconsider missile test moratorium if Washington doesn't resume contacts aimed at normalizing relations.

-- July 2001: US State Department reports North Korea developing long-range missile.

-- December 2001: US President Bush warns Iraq and North Korea will be "held accountable" if they develop weapons of mass destruction.

-- January 29, 2002: Bush labels North Korea, Iran and Iraq an "axis of evil."

-- October 4, 2002: North Korea tells visiting US delegation it has a second covert nuclear weapons program, Washington says.

-- November 11, 2002: US and key Asian allies, Japan and South Korea, halt oil supplies to North promised in 1994 deal.

-- January 10, 2003: North Korea says it will withdraw from Nuclear Nonproliferation Treaty.

-- April 16, 2003: US, Chinese and North Korean officials announce talks in Beijing aimed at ending nuclear standoff.

-- April 24, 2003: North Korea says it has nuclear weapons and may test, export or use them depending on US actions, Washington says.

-- August 27-29, 2003: North Korea joins first round of six-nation nuclear talks in Beijing, which include China, US Japan, Russia and South Korea.

-- February 25-28, 2004: Second round of six-nation talks.

-- June 23-26, 2004: Third round of six-nation talks.

-- September 2004: North Korea refuses to attend fourth round talks, accusing US of "hostile" policies.

-- February 10, 2005: North Korea announces it has nuclear weapons.

-- July 26, 2005: Fourth round of six-nation talks begins, ends in recess after 13 days with no agreement.

-- September 13, 2005: Talks resume.

-- September 15, 2005: US blacklists a Macau-based bank for alleged involvement in North Korea's illicit activity such as money laundering and counterfeiting, leads the bank to freeze North Korean assets.

-- September 19, 2005: North Korea pledges to dismantle nuclear programs in exchange for pledges of energy assistance; US pledges not to invade and to respect North's sovereignty in an agreement ending talks.

-- November 9-11, 2005: Fifth round of six-nation talks.

-- January 3, 2006: North Korea says it won't return to talks unless the US lifts financial restrictions imposed for its alleged currency counterfeiting and other illegal activities.

-- March 7: North Korean, US officials meet in New York for talks over US financial restrictions.

-- July 5: North Korea launches seven missiles into the Sea of Japan, including a long-range Taepodong-2, drawing international condemnation an a later UN Security Council resolution condemning it.

-- September 26: North Korea rejects further talks on its nuclear program, claims Washington wants to rule the world.

-- October 3: North Korea says it will conduct a nuclear test in the face of what it claimed was "the US extreme threat of a nuclear war."

-- October 9: North Koreas says it has conducted its first-ever nuclear test.