TIMELINE: Iran's nuclear program

(Reuters) - Here is a chronology of events since it first emerged Iran was carrying out sensitive work that it could use to make atomic bombs. Iran says its program is for peaceful energy generation.

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

February 4 - IAEA votes to report Iran to the U.N. Security Council. Iran ends snap U.N. nuclear inspections the next day.

February 14 - Iran restarts small-scale feeding of uranium gas into centrifuges at Natanz after two-and-a-half year suspension.

April 11 - Ahmadinejad declares that Iran has produced its first batch of enriched uranium. World powers condemn Iran for advancing its program in defiance of the United Nations.

June 5 - EU foreign policy chief Javier Solana delivers a package of incentives from world powers if Iran agrees to halt uranium enrichment.

August 31 - IAEA announces Iran has not met a deadline to suspend its atomic fuel program.

December 23 - Security Council votes for sanctions and gives 60 days to suspend enrichment. Iran calls the resolution illegal.

March 24, 2007 - The Security Council unanimously approves further arms and financial sanctions against Iran.

April 18 - IAEA says Iran has started up more than 1,300 centrifuge machines in an accelerating campaign to lay a basis for "industrial scale" enrichment in the Natanz complex.

August 21 - Iran and the IAEA say they agreed a timeline for answering outstanding questions about Iran's nuclear program.

October 24 - The United States imposes new sanctions on Iran and accuses its Revolutionary Guard of spreading weapons of mass destruction.

November 2 - Britain, France, Germany, the United States, Russia and China agree to push ahead with a third round of tougher sanctions.

December 3 - A U.S. National Intelligence Estimate says Iran put its bid to build a nuclear bomb on hold in 2003 and it remains on hold.

December 5 - Ahmadinejad declares victory over the U.S. and IAEA head Mohamed ElBaradei says Iran has been "somewhat vindicated".

December 11 - The opposition NCRI says Iran did shut down its program in 2003 but restarted it a year later. The group says a recent U.S. analysis gives the wrong impression.

January 11-12, 2008 - ElBaradei makes a rare visit to Tehran to push for swifter cooperation in wrapping up the IAEA inquiry.

February 22 - An IAEA report paints a more positive picture of Iranian cooperation than before, but also confirms Iran was testing technology that could give it the means to enrich uranium much faster -- in further defiance of Western demands.

March 3 - U.N. Security Council adopts third sanctions resolution targeted at Iran's nuclear program.

April 8 - Ahmadinejad says Iran has started to install 6,000 advanced centrifuges at its Natanz enrichment plant.

April 16 - World powers looking to revive negotiations with Iran fall short of agreeing on a new package of incentives.

May 2 - Britain says major powers have agreed to make a new offer of incentives. Days later Iran says it will not agree to incentives that violate its nuclear rights.

May 13 - Iran says it has presented proposals on global issues including its nuclear program to EU's foreign policy chief Javier Solana.

May 14 - Russia's foreign minister says that the 'Six' could directly put concrete offers on the negotiating table and could guarantee Tehran's security. The White House later says security guarantees for Iran were not being considered.

May 26 - The IAEA says Iran's alleged research into nuclear warheads is a matter of serious concern and Tehran should provide more information on its missile-related activities.

(Writing by David Cutler, London Editorial Reference Unit;)