WASHINGTON, Jan. 24 (Xinhuanet) -- The U.S. troops levels in Iraq have dropped to the lowest point since last summer, when a buildup for election protection expanded the force to about 160,000, the Pentagon said Tuesday.

    After extra forces, put in place during Iraq's October constitutional referendum and the December parliamentary elections,have been removed and a rotation of major combat units has largely been completed, there are now about 136,000 U.S. troops in Iraq, said Barry Venable, a Pentagon spokesman.

    Earlier, George Casey, the top U.S. commander in Iraq, said last month that he expects the troop levels to draw down further, to about 130,000 by March.

    Pentagon officials have suggested troop levels could be cut much more later this year, possibly to the level of 100,000, if conditions in Iraq are favorable for such moves.

    In the beginning of 2004, the U.S. troop levels in Iraq had once dropped to about 110,000.

    However, after that, the U.S. military had to keep reinforcing its troops due to growing insurgency.

    As of Monday, 2,236 U.S. troops had been killed in Iraq since the beginning of the war in March 2003. Enditem