FACTBOX: Sanctions on Iran and what could follow

(Reuters) - France said on Tuesday it would continue to press for a third round of U.N. sanctions against Iran despite a U.S. intelligence report that said Tehran had halted its nuclear weapons program.

The U.S. National Intelligence Estimate (NIE) report released on Monday took U.S. friends and foes by surprise after years of strident rhetoric from Washington accusing Iran of pursuing a covert nuclear weapons program.

Following are details about what another U.N. resolution could involve and what sanctions have been imposed on Iran by the U.N. Security Council and the United States.

* WHAT COULD MORE U.N. SANCTIONS INCLUDE?

-- A possible third round of sanctions is expected to be the object of fierce debate between Security Council members, but French Foreign Minister Bernard Kouchner has said they could range from financial and investment freezes to travel and visa bans, an arms embargo and possible restrictions on oil trading.

* WHAT SANCTIONS HAVE BEEN IMPOSED ON IRAN?

* UN SANCTIONS:

-- The U.N. Security Council has imposed two sets of mild sanctions on Iran, the first resolution was passed in December 2006 and a second approved in March 2007.

-- Both sets of sanctions were approved unanimously after wrangling between the five permanent Council members -- the United States, France, Britain, China and Russia -- plus Germany, in the so-called P5+1.

-- THE FIRST ROUND: The sanctions covered sensitive nuclear materials and froze the assets of Iranian individuals and companies associated with the program. It gave Iran 60 days to suspend uranium enrichment, a process which can be used to make nuclear power plant fuel or bomb material. Iran did not stop.

-- THE SECOND ROUND: The resolution in March included new arms and financial sanctions. It extended an asset freeze to 28 additional groups, companies and individuals engaged in or supporting sensitive nuclear activities or development of ballistic missiles.

-- State-run Bank Sepah and commanders and firms controlled by Iran's Revolutionary Guards, including commanders of one of its units, the Qods Force, were included on the list.

-- The resolution invoked Chapter 7, Article 41 of the U.N. Charter, which makes most of its provisions mandatory but excludes military action. Iran again failed to meet a 60-day deadline to halt enrichment.

* U.S. SANCTIONS:

-- The United States has imposed various sanctions on Iran since 1979 after radical Iranian students stormed the U.S. embassy in Tehran and took U.S. diplomats hostage.

-- The measures prohibit most trade between the United States and the Islamic Republic.