Feb 1993: International Atomic Energy Agency requests inspection of two nuclear waste storage sites, citing evidence that North Korea has been cheating on its nuclear non-proliferation treaty commitments. North Korea refuses.

Mar 1993:: North Korea announces intention to withdraw from the NPT, but later relents.

Jun 1994:: Former US president Jimmy Carter negotiates a deal with North Korea to freeze its nuclear arms programme.

Oct 1994:: US and North Korea sign Agreed Framework, committing Pyongyang to freeze and eventually end weapons development and allow IAEA inspections. In return, North Korea would receive international aid including two light-water reactors and annual heavy fuel oil shipments.

Aug 1998:: North Korea test fires its 2,000 km-range Taepodong-1 missile over Japan. Work continues on the 6,000km-range Taepodong-2 missile capable of reaching the US.

Dec 1999:: An international consortium signs a $4.6bn US contract to build two light water nuclear power plants in North Korea.

Jan 2002:: President Bush describes North Korea as part of an 'axis of evil' in State of the Union address.

Oct 2002:: James Kelly, US assistant secretary of state, visits Pyongyang and secures an admission that North Korea has an active programme enriching uranium to weapons grade, contravening the Agreed Framework.

Nov 2002:: United States and 13 states belonging to the Korean Peninsula Energy Development Organisation meet in New York and decide to cut off heavy fuel oil shipments to Pyongyang.

Dec 2002:: North Korea says it plans to restart its Yongbyon reactor shut under 1994 deal, disables IAEA surveillance devices at Yongbyon and expels IAEA inspectors.

Jan 2003:: North Korea quits the NPT.

Feb 2003: US “prepare to deploy” order signed that will send 24 bombers to Pacific region. North Korea threatens to abandon 1953 Korean War armistice if US military deployment continues.

Apr 2003:: At a meeting in Beijing, North Korea tells the US that it has nuclear weapons and may test them or export them to other countries.

May 2003: North Korea announces its withdrawal from 1992 nuclear non-proliferation agreement with South Korea.

Jul 2003: US claims North Korea has started to reprocess 8,000 spent plutonium fuel rods from Yongbyon.

Aug 2003: Six-party talks among the two Koreas, the US, China, Japan and Russia open in Beijing, but end in confusion as Washington says Pyongyang announced its intention to declare itself a nuclear state.

Jan 2004: Pyongyang lets an unofficial US delegation of scientists and government officials tour Yongbyon and shows them what appears to be weapons-grade plutonium

Feb 2004: The father of Pakistan's nuclear bomb, scientist Abdul Qadeer Khan, admits to sharing uranium-linked technology with Libya, Iran and North Korea. North Korea denies the claim. Second round of six-party talks fails to make any headway

Jun 2004: In third round of six-party talks, US offers fuel aid in exchange for North Korea freezing and dismantling its nuclear programmes.

Sep 2004: North Korea tells UN General Assembly it has converted plutonium from 8,000 spent Yongbyon fuel rods into nuclear weapons.

Jan 2005: Condoleezza Rice calls North Korea one of the world’s six “outposts of tyranny”.

Feb 2005: North Korea declares it has manufactured nuclear weapons and announces its withdrawal from six-party talks.

Mar 2005: North Korea says it will no longer abide by the missile test ban treaty.

Apr 2005: Intelligence suggests Yongbyon reactor has been shut down, possibly to extract more fuel for nuclear weapons.

May 2005: North Korea launches a short-range missile into the Sea of Japan, says it has successfully removed thousands of spent fuel rods at Yongbyon and is “taking measures to enhance our nuclear arsenal.”

Jul 2005: Fourth round of six-party talks begin in Beijing. After 13 days of talks and five draft agreements the talks are put on hold for three weeks.

Sep 2005: North Korea agrees to abandon all its nuclear programmes in return for pledge from the other five parties to discuss supplying a light-water reactor “at an appropriate time” and a non-aggression pledge from the US. US imposes financial sanctions on a Macao bank and eight North Korean companies that it alleges have been involved in counterfeiting and money laundering

Nov 2005:: Fifth round of talks collapses after three days.

Mar 2006: North Korea test-fires two short-range missiles from a coastal site on the Sea of Japan.

Jun 2006: Pyongyang invites Christopher Hill, Washington’s top negotiator in the six-party talks, to visit for bilateral discussions. The US rejects the offer.

Jul 2006: North Korea launches seven missiles, including a long range Taepodong-2 with the theoretical capacity of reaching the continental US, but which fails 40 seconds into its flight.

Sep 2006: Selig Harrison, an American scholar, returns from Pyongyang with news that North Korea is planning to unload fuel rods at its Yongbyon reactor within three months.

Oct 3, 2006: Saying it needed to “bolster its war deterrent for self-defence”, Pyongyang said it would “in the future conduct a nuclear test”, sparking international alarm.

Oct 6 2006: The UN Security Council unanimously warns North Korea against testing, following strong statements by Japan, South Korea, China, the US and others.

Oct 9 2006: North Korea announces that it has carried out an underground nuclear test.
Financial Times