Early signs show President Bush's Iraq troop buildup plan may be working, he said, but it's too early to know the success of the most recent operation being led by Gen. David Petreaus, the new head of Multinational Forces in Iraq.

Bush noted that more Iraqi troops have deployed in Baghdad, as promised and more joint U.S. Iraqi patrols have been doing sweeps of the Shiite stronghold of Sadr City.

"It's too early to judge the success of this operation. ... But even at this early hour there are some encouraging signs," Bush told an audience of 860 gathered at the American Legion conference in Washington, D.C.

Amid partisan bickering over war strategy, Bush in January announced that 21,500 more troops would be sent to Baghdad and the Anbar province to try to stop sectarian violence. Bush coupled the buildup with new benchmarks for the Iraqi government to achieve.

Bush said the government led by Prime Minister Nouri al-Maliki has kept its pledge to deploy three additional Iraqi army brigades to Baghdad and has lifted restrictions that prevented coalition and Iraqi forces from going into certain areas. He added that tactics have changed so that guard stations are no longer deserted after fighting has ended in an area and troops now remain to ensure the silence.

While providing a progress report in the War on Terror, Bush also named a decorated war veteran and former Clinton cabinet member as leaders of a commission to investigate soldiers' treatment at Walter Reed Army Medical Center.

Bush said former Kansas Sen. Bob Dole and former Heath and Human Services Secretary Donna Shalala, now president at the University of Miami, will co-chair the commission.

The panel will review conditions at the Army's flagship hospital after the recent uncovering of poor treatment of soldiers there. It will also look at broader treatment throughout military hospitals.

"I am as concerned as you are about the conditions at Walter Reed Army Medical Center. My decision has put our kids in harm's way and I'm concerned about the fact that when they come back, they don't get the full treatment they deserve," Bush said that most of the doctors and nurses at the hospital are exemplary, "yet some of our troops at Walter Reed have experienced bureaucratic delays" and other problems.

"It's unacceptable to me. It's unacceptable to you. It's unacceptable to our country. It's not going to continue," Bush said.

"We have a moral obligation to provide the best possible care and treatment to the men and women who serve this country. They deserve it and they're going to get it," Bush said to applause.

White House spokeswoman Dana Perino said the commission will have nine members and will report back to the president by June 30. She said among the panel's tasks, it will approve procedures for transferring soldiers from deployment to civilian life, assure high quality services are available to returning service members and make sure they have increased access to benefits and services.

Bush also has asked Veterans Affairs Secretary Jim Nicholson to head an interagency task force that will report back with ways to improve veterans' care.

While soldiers' conditions are reviewed at home, the conditions on the ground in Baghdad have improved. Bush said Iraqi and U.S. forces have rounded up more than 700 people affiliated with Shiite extremists, and also have launched successful operations against Sunni extremists.

But while violence has dropped in the capital, U.S. military officials say insurgents have fled Baghdad for outlying areas, where attacks are on the rise.

The president also highlighted individual successes in turning up weapons caches, killing insurgents and building joint security stations that are designed to hold neighborhoods secured by U.S. and Iraqi forces.

Bush reiterated the stance he's held throughout the war in Iraq, that terrorists and extremists must be fought on foreign soil or they will attack Americans on U.S. soil like they did on Sept. 11, 2001, and the fight in Iraq is part of a broader struggle against extremism in the Middle East.

"If we fail in Iraq, the enemy will follow us home," Bush said.

Bush argued against political tactics being pursued by Democrats, some who are seeking to limit troop movements by imposing readiness restrictions and others who are looking at benchmark proposals that would say when the troops would return.

"Now that the battle for Baghdad is underway, our country is best served by standing behind our troops and doing everything we can to aid in their success," Bush said. " The outcome of this conflict involves more than the fortunes of any one president, or any political party. This mission is America's mission. And our failure would be America's failure."

The Associated Press contributed to this report.