Washington has ordered a review of the way wounded US soldiers are cared for at military hospitals, following highly critical reports in the US media.
The White House says any problems should "get fixed"
A top defence official has admitted one hospital, Walter Reed, had problems that must be fixed "immediately".
Reports in the Washington Post said some of the soldiers wounded in Iraq and Afghanistan lived in buildings infested with rodents and cockroaches.
It said others had to wait for months to get their disability pay.
Dr William Winkenwerder, assistant defence secretary for health affairs, said trust in the Army had "taken a hit" following complaints about living conditions at some Walter Reed buildings.
General Richard Cody, vice-chief of staff of the Army, added that he had visited some of the rooms and found them "disappointing".
He pledged to oversee personally the reconstruction of the building he inspected, which is known as Building 18.
White House spokesman Tony Snow said the men and women who fought for the US deserved "the best care".
"There's plenty of outrage," Mr Snow said, responding to the Washington Post's investigation into how some 700 wounded soldiers were being treated at Washington's Walter Reed Army Medical Center.
"We need to make sure that whatever problems there are get fixed," the White House spokesman said.
The Pentagon said an independent panel would look into outpatients and administrative processes at Walter Reed and also at the National Naval Hospital in Maryland.
The Pentagon said that the army and the navy had also begun their own reviews of America's top two medical facilities.
In the US Congress, Democratic lawmakers said they were appalled by the reports' findings and promised to push for legislation to improve conditions at military hospitals.
The reports put the White House - which is trying to win public support for its handling of the war in Iraq - in a difficult position, the BBC's Emilio San Pedro says.
After all, President George W Bush has often spoken of America's debt to the country's military personnel for their service in Afghanistan and Iraq, our correspondent says.