FACTBOX: U.S. military "surge" in Iraq troop level

(Reuters) - Gen. David Petraeus, the top U.S. commander in Iraq, and Ambassador Ryan Crocker update Congress on Tuesday on progress made during a "surge" of force in the war zone credited with helping to reduce violence. Here are facts about the surge strategy and its goals.

SURGE STRATEGY

President George W. Bush ordered the U.S. military to increase troop levels in Iraq in January 2007 under a strategy known commonly as the "surge" that included security, political, economic and regional components.

--Five brigade combat teams, including about 20,000 combat troops and another 10,000 support personnel, were sent to Iraq from February to mid-June. The Pentagon also requested Congress to increase the total size of the Army and Marine Corps to help ease the strain on the force from the Iraq war.

--Iraq agreed to deliver additional Iraqi forces to Baghdad and to bar political officials from interfering with security operations.

--The aim of the surge was to help Iraqi soldiers reduce sectarian violence and create what Bush called "breathing space" for Iraqi officials to make progress on legislative initiatives seen by Washington as critical to long-term stability.

GOALS FOR THE IRAQI GOVERNMENT:

--Take responsibility for security in all of Iraq's provinces by November 2007

--Give U.S. and coalition forces authority to pursue all extremists