(Bloomberg) -- President George W. Bush called 2005 a "year of progress" in Iraq and said the U.S. will reduce the number of its troops there by "several thousand" because Iraqis are taking more responsibility for their own security.

The U.S. over the next year will cut its forces in Iraq below levels that were set before the Iraqi elections, Bush said today at the Pentagon. The U.S. also plans to reduce the number of its troops in Afghanistan, he said.

"If Iraqis continue to make progress on the security and political sides that we expect, we can discuss further possible adjustments with the leaders of a new government in Iraq, " Bush said after being briefed by Defense Department officials.

The U.S. has about 160,000 troops in Iraq, including extra soldiers and Marines dispatched to provide greater security for Iraqi elections. Bush said about 20,000 of the extra troops will pull out of Iraq and the overall force level will drop below the 138,000 that had been the baseline before the elections.

Defense Department officials previously outlined possible troop reductions in 2006. Several countries that were part of the U.S.-led coalition in Iraq have announced they will withdraw or scale back their forces in Iraq this year, including Ukraine, Italy and South Korea.

"As see more of these Iraqi forces in the lead, we are going to continue with our desired strategy that, as the Iraqis stand up, we stand down," Bush said. "The adjustment is underway."

Congressional Pressure

U.S. combat losses have increased pressure in Congress from Democrats and some Republicans for Bush to outline a strategy to reduce the U.S. military commitment in Iraq. He said today that along with reducing the number of troops, U.S. forces will take on fewer combat operations and concentrate on training and support of Iraqi police and armed forces.

"But my decisions will be based on discussions with leaders on the ground, not false timetables in Washington, D.C.," Bush said. "I am not going to let politics get in the way and people need to understand that."

Three elections marked by high turnout over the past year are a "real defeat" for the terrorists and insurgents who have been attacking U.S. and Iraqi targets, Bush said. The U.S. will continue handing over more responsibility and territory to Iraqi authorities over the next year, he said.

Bush also said that he plans on cutting the U.S. troop level in Afghanistan from 19,000 to 16,500, in part because the nations of the North Atlantic Treaty Organization are providing more forces to support the Afghan government.

"The international community is stepping up," Bush said.