CHRONOLOGY: Iran's nuclear program
(Reuters) - Iran has prepared a package of proposals to try to defuse a nuclear row with world powers, chief nuclear negotiator Saeed Jalili said on Monday after talks with a top Russian official.
Separately, the International Atomic Energy Agency's top investigator, Olli Heinonen, arrived in Tehran to discuss international accusations that Iran researched how to make nuclear bombs.
Here is a chronology of events since it emerged that 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 had 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.
Aug 21 - Iran and the IAEA say they agreed a timeline for answering outstanding questions about Iran's nuclear program.
Oct 24 - The U.S. imposes new sanctions on Iran and accuses its Revolutionary Guard of spreading weapons of mass destruction.
Nov 2 - Britain, France, Germany, the U.S., Russia and China agree to push ahead with a third round of tougher sanctions.
Dec 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.
Dec 5 - Ahmadinejad declares victory over the U.S. and IAEA head Mohamed ElBaradei says Iran has been "somewhat vindicated".
Dec 11 - The opposition NCRI says that 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.
Jan 11-12, 2008 - ElBaradei makes a rare visit to Tehran to push for swifter cooperation in wrapping up the IAEA inquiry.
Feb 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 2008 - U.N. Security Council adopts third sanctions resolution targeted at Iran's nuclear program.
April 8 - Ahmadinejad says that 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 to present Tehran. In Tehran, Ahmadinejad says Iran is ready for negotiations if such talks do not violate country's rights.
April 22 - Iran describes as "positive" two days of talks with IAEA's top investigator, Olli Heinonen.
(Writing by David Cutler, London Editorial Reference Unit;)
