A U.S. Army soldier escorts a suspected al-Qaida member in Baqouba, Iraq, Sunday, July 8, 2007. Some 33 suspects were arrested in a joint U.S. and Iraqi overnight raid Sunday. [AP]

President Bush's top war advisers, Lt. Gen. Douglas Lute and Stephen Hadley, went to Capitol Hill to assure Republican supporters that a precipitate pullout of troops won't happen. Sens. Trent Lott of Mississippi, Lindsey Graham of South Carolina, John McCain of Arizona, Jon Kyl of Arizona and others met with the two advisers in Vice President Dick Cheney's office off the Senate floor.

Graham said members were told that Bush would back them in fiercely opposing legislation by Sen. Carl Levin, D-Mich., that would order troop withdrawals to start in 120 days.

Bush himself said Tuesday he had no intention of succumbing to political pressure. During a visit to Parma, Ohio on Tuesday, he reiterated that troop levels in Iraq "will be decided by our commanders on the ground, not by political figures in Washington, D.C."

"I fully understand that this is a difficult war. It's hard on the American people but I will once again explain the consequences of failure," he said.

Graham told reporters the White House is looking at new ways to hasten progress in two primary areas: destroying al-Qaida in Iraq and forcing the U.S.-backed government in Baghdad to make political progress.

"I think you're going to find a united front at the White House and to give Gen. (David) Petraeus the time he needs to do nothing to undercut the surge" of troops, Graham said.

A key progress report being briefed to members Thursday will say the Iraqi government has not met any of its targets for reform but has made some progress in about more than a half-dozen areas, including tamping down violence in Anbar province.

Democrats said the only way Baghdad and its neighbors would take more responsibility in Iraq would be if the U.S. starts to pull out.

Levin, D-Mich., and Sen. Jack Reed, D-R.I., want legislation that would order Bush to begin pulling out troops in four months and end combat by April 30, 2008. The measure would allow for some troops to remain to conduct counterterrorism, train the Iraqi security forces and protect U.S. infrastructure.

"There is much too little pressure on Iraqi leaders to do what they have to do," said Levin, chairman of the Armed Services Committee.

White House spokesman Tony Snow earlier Tuesday downplayed the significance of the report coming later in the week, calling it only "a look at the starting line" of the U.S. troop surge.

Levin's proposal, offered as an amendment to a $649 billion defense policy bill, is expected to fail because Republicans say they still oppose setting timetables.

But in a sign that GOP frustration with the war is growing, Sen. Gordon Smith, R-Ore., said he would co-sponsor Levin's measure and Olympia Snowe, R-Maine, said she was considering switching her position and backing the measure. Sen. Chuck Hagel, R-Neb., was considered another likely supporter.

Sen. Susan Collins, Ben Nelson, D-Neb., and other moderates said they were considering an alternative proposal that would demand an end to combat and allow U.S. troops to conduct only a narrow set of missions. The measure would not identify a date.

"What many of us are looking for is a new strategy that would not be a precipitous pullout with all of the problems that would cause, but rather a plan to exit over the next year," said Collins, R-Maine.

Sen. John McCain, upon his return from Iraq, defended Bush's build up, contending reinforcements had only just recently been put in place.

"I believe that our military in cooperation with our Iraqi security forces are making progress in a number of areas," he said, noting specifically a dramatic drop in attacks in Ramadi in the western Anbar province.

Reed of Rhode Island, who also visited Iraq last week, said that Petraeus, the top commander in Iraq, told him the limits of U.S. military resources will factor into his recommendation on what to do next. "Come next spring, the ability to generate 160,000 soldiers and Marines in country virtually comes to an end," said Reed.