Timeline: Iran's nuclear program

(Reuters) - The Pentagon said on Tuesday that the United States wanted a U.N. Security Council resolution "within weeks" to tackle Iran's nuclear program as Iran said it had begun making higher-grade nuclear fuel.

Here is a timeline of Iran and its nuclear program in the last year:

March 20, 2009 - After years of U.S. attempts to isolate Iran, newly installed President Barack Obama calls for "engagement that is honest and grounded in mutual respect." Iran cautiously welcomes the overture, but wants practical steps.

April 9 - Iranian President Mahmoud Ahmadinejad says Iran has mastered the nuclear fuel cycle and also tested more advanced machines for enriching uranium. He inaugurates the country's first atomic fuel fabrication plant near Isfahan.

June 5 - A quarterly report by U.N. nuclear watchdog IAEA says Iran has 7,231 centrifuge enrichment machines installed, a 25 percent increase in potential capacity since March.

June 12 - Ahmadinejad is re-elected president. Protests break out by moderates who say the result was fixed.

September 2 - IAEA chief Mohamed ElBaradei says Iran is not going to produce a nuclear weapon in the near future and the threat posed has been exaggerated.

September 24 - China dampens expectations of further sanctions against Iran, telling major powers more pressure will not persuade Tehran to halt its nuclear program.

-- In contrast, British Prime Minister Gordon Brown tells the United Nations the world should consider tougher sanctions.

September 25 - The IAEA says Iran has told it about a second uranium enrichment plant being built. Construction of the plant, near the city of Qom, began in 2006.

October 1 - Iran meets six world powers in Geneva. Iran accepts a plan at the talks to send 75 percent of its low-enriched uranium (LEU) to Russia and France. There it would be made into special fuel for a Tehran reactor making medical materials.

October 21 - IAEA presents draft deal to reduce Iran's stockpile of enriched uranium.

October 25 - U.N. nuclear experts inspect the newly disclosed centrifuge plant being built near the Shi'ite holy city of Qom. The site will refine uranium for civilian nuclear energy.

October 30 - Iran tells IAEA it wants fresh nuclear fuel for a reactor in Tehran before it will agree to ship some enriched uranium stocks to Russia and France, according to the U.N.

November 18 - Iran says that Tehran will not send its enriched uranium abroad for further processing but would consider swapping it for nuclear fuel within its borders.

November 19 - Obama issues a strong warning to Iran of consequences of its failure to respond to the nuclear deal.

November 24 - World powers have drafted an IAEA resolution urging Iran to clarify the purpose of its previously secret uranium enrichment site, diplomats say.

-- Iran could consider sending its low-enriched uranium abroad, the Foreign Ministry says, apparently softening its opposition to a U.N. plan.

November 26 - ElBaradei criticizes Iran's blockage of a plan to divest it of possible nuclear bomb material as "disappointing."

November 27 - The IAEA votes -- by a 25-3 margin with six abstentions -- to censure Iran for developing the Fordow uranium enrichment plant near Qom in secret and demand Iran freezes the project.

November 29 - Iran announces plans to build 10 more nuclear sites in a swipe at growing pressure to rein in its atomic work.

January 19, 2010 - Diplomats say Iran has formally rejected key parts of the deal to send abroad for processing most of its material that could be used to make nuclear arms.

January 21 - Russia says it will start up the reactor at Iran's long-delayed Bushehr nuclear power plant.

February 2 - Ahmadinejad announces Iran is ready to send its enriched uranium abroad in what appears to be an easing of its position. The next day it launches a Kavoshgar-3 rocket capable of carrying a satellite, a move Washington describes as a "provocative act."

February 4 - China's foreign minister, Yang Jiechi, says during a visit to France, Tehran's negotiating position is evolving and he wants to see more direct talks with Iran.

February 9 - Iran begins making higher-grade nuclear fuel, enriched to a level of 20 percent, at its Natanz facility. Iran announced its intentions on February 7 and the IAEA confirmed Iran's plans the next day.