Timeline: Path to join the 'N-technology club'

Following is a timeline of key developments in the international stand-off over Iran's nuclear programme after Tehran on Tuesday said it had succeeded in enriching uranium.

2002
Dec 12-13: Satellite photographs shown on US television reveal the existence of nuclear sites at Arak, southwest of Tehran, and Natanz, in central Iran, which US media say may have a military use. Iran agrees to International Atomic Energy Agency (IAEA) inspection.

2003
Feb 9: President Mohammad Khatami says uranium deposits have been discovered in Iran and Tehran is building two factories to convert the ore into nuclear power station fuel.

Aug 26: A confidential UN report reveals Iran has developed two kinds of enriched uranium not needed for peaceful energy production.

Nov 10: An internal IAEA report states "at the moment, there is no proof that Iran is creating nuclear weapons", a conclusion the United States disputes.

Dec 18: Iran signs an additional protocol to the nuclear Non-Proliferation Treaty allowing unannounced inspections of nuclear sites. Protocol must still be ratified by parliament.

2004
June 1: IAEA claims to have found traces of enriched uranium that exceed the levels necessary for civilian energy production.

July 31: Iran admits to having resumed production of parts for centrifuges.

Sept 21: Says it has resumed large-scale conversion of uranium ore.

Nov 14: Iran accepts complete suspension of uranium enrichment activities.

Nov 22: Suspension of enrichment takes effect.

2005
Feb 27: Iran and Russia sign a nuclear fuel accord that paves the way for the start-up of the Bushehr nuclear plant. Russia will fuel the reactor on condition Iran sends back spent fuel.

Aug 3: President Mahmoud Ahmadinejad takes office.

Aug 5: Tehran rejects an EU offer of a broad package of incentives aimed at ending the standoff.

Aug 8: Iran resumes uranium conversion work at Isfahan and later removes IAEA seals.

Aug 12: US President George W. Bush refuses to rule out the use of force against Iran.

Sept 20: Iran threatens to resume enrichment, prevent UN inspections of its nuclear sites and abandon NPT if it is referred to the Security Council.

Sept 24: IAEA passes a resolution that reserves the right to send Iran's case to the UN Security Council but Russia and China abstain.

Nov 11: Russia presents a plan, endorsed by EU and agreed to by the United States, that would allow Iran to continue uranium enrichment but on Russian soil.

2006
Jan 3: Iran announces the resumption of nuclear research activities that had been suspended for two years.

Jan 7: Talks between Russia and Iran end without a result.

Jan 10: Iran removes IAEA seals placed on enrichment-related equipment at Natanz.

Feb 4: IAEA votes by a large majority to report Iran to the Security Council, leaving the door open to sanctions. It puts off any UN action to allow time for diplomacy before a regular March 6 IAEA meeting. Iran retaliates by saying it will limit UN inspections.

Feb 14: Tehran says it has begun small-scale enrichment at Natanz.

March 1: Talks with Moscow fail after Iran insists on continuing to enrich on its own soil.

March 3: Iran-EU3 talks collapse. Iran proposes two-year moratorium on industrial enrichment but insists on continuing research at Natanz.

April 3: Iran begins military manoeuvres in Gulf, including testing of new missiles

April 11: Ahmadinejad says Iran has joined the atomic club and calls for acceleration of programme, as officials confirm successful enrichment. White House says Iran moving in "wrong direction".

April 12: Russia and Germany echo US position, and Israel calls nuclear Iran threat to world.