Timeline of Iran's nuclear programme

(Reuters) - U.N. nuclear watchdog chief Mohamed ElBaradei sought clarity from Iran on Friday about an atomic programme the West fears may ultimately yield warheads.

On his first Iran trip in almost two years, ElBaradei began talks with Iranian atomic energy chief Gholamreza Aghazadeh.

Here is a chronology since it emerged that Iran was carrying out sensitive work that it could use to make atomic bombs.

August 2002 - The exiled opposition National Council of Resistance of Iran reports the existence of uranium enrichment facility at Natanz and heavy water plant at Arak.

December 2002 - The United States accuses Iran of "across-the-board pursuit of weapons of mass destruction".

June 2003 - An IAEA report, after February inspection of Natanz and Arak, says Iran has failed to comply with nuclear Non-Proliferation Treaty.

November 2004 - Iran promises EU negotiators it will suspend all nuclear fuel processing and reprocessing work.

September 2, 2005 - IAEA report confirms Iran has resumed uranium conversion at Isfahan.

January 10, 2006 - Iran removes U.N. seals at Natanz enrichment plant and resumes nuclear fuel research.