Updated

President Bush is not contemplating withdrawing forces from Iraq now despite an erosion of support among Republicans for his war policy, the White House said Monday.

The administration also tried to lower expectations about a report due Sunday on whether the Iraqi government is meeting political, economic and security benchmarks that Bush set in January when he announced a buildup of 21,500 U.S. combat forces. White House press secretary Tony Snow said that all of the additional troops had just gotten in place and it would be unrealistic to expect major progress now.

"You are not going to expect all the benchmarks to be met at the beginning of something," Snow said. "You are hoping that you are going to be able to see progress in terms of meeting benchmarks from that beginning stage to what you see in two months."

But at the same time, he said that Sept. 15 is not "the drop dead date" by which everything should be completed.

Defense Secretary Robert Gates shortened a planned trip this week so he would be in Washington to attend policy meetings aimed at coming up with the report to Congress.

In Florida for a military ceremony, Gates participated in a video conference Monday morning with the president's national security team, said Defense Department spokesman Bryan Whitman. He was to have continued on to Latin America, but changed his plans so he could return to Washington Monday afternoon.

Asked if Pentagon officials were studying a change in Iraq strategy, Whitman would say only that the military is "focused on implementing" the current strategy.

Bush is under growing pressure even within his own party to shift course in Iraq as the war drags on and casualties climb. At least 3,605 members of the U.S. military have died since the war began in March 2003. Bush's approval rating in the polls has sunk to record lows.

Sen. Susan Collins of Maine, ranking Republican on the Homeland Security Committee, said there had been "a steady erosion for the president's policy" in Congress because of the "tremendous loss of life among our troops" in June and "the failure of the Iraqi government to pursue the political reforms that are necessary to quell the sectarian violence."

Earlier this year Bush vetoed legislation that would have set a deadline for U.S. troop withdrawals. In recent days three Republicans — Sens. Richard Lugar of Indiana, George Voinovich of Ohio and Pete Domenici of New Mexico — have announced they can no longer support Bush's Iraq strategy and have called on the president to start reducing the military's role there.

"There is no debate right now on withdrawing forces right now from Iraq," Snow said.

"The president has said many times that as conditions require and merit that there will be in fact withdrawals and also pulling back from areas of Baghdad and so on," the press secretary said. "But the idea of trying to make a political judgment rather than a military judgment about how to have forces in the field is simply not true."