"You are courageously leading our nation in the war on terrorism. You are doing a superb job," Mr. Bush said. "You are a strong secretary of defense and our nation owes you a debt of gratitude."
The president called the alleged abuses "an affront to the most basic standards of morality and decency."
He promised that, "All prison operations in Iraq will be thoroughly reviewed to make sure such abuses are not repeated."
But he defended the American mission in Iraq as being vital to the country's future and U.S. national security. In spite of the abuse, Mr. Bush asked, "Who can doubt that Iraqi is better being free?"
Several prominent Democrats and newspapers have called for Rumsfeld's departure. But Sen. Joseph Biden of Delaware told the CBS News Early Show that while he thinks Rumsfeld should resign, he also feels too much is being made of the question of Rumsfeld's continuance in office.
"I think this is somewhat bigger than Secretary Rumsfeld," the ranking Democrat on the Senate Foreign Relations committee said. "I want to see the president do some swift and positive action here. Rumsfeld is part of the problem, not part of the solution. I don't care if he goes stand in a corner."
Mr. Bush's trip across the Potomac River to the Pentagon comes a day after it was announced that Spc. Jeremy C. Sivits, 24, of Hyndman, Pa.,in connection with the abuse. He will be tried May 19 in Baghdad on charges of mistreating detainees. In all, seven soldiers face abuse allegations.
Sivits, 24, has been charged with conspiracy to maltreat subordinates and detainees, dereliction of duty for negligently failing to protect detainees from abuse and cruelty and maltreatment of detainees, military spokesman Brig. Gen. Mark Kimmitt said.
Kimmitt said Sunday the trial will be held in Baghdad and will be open to media coverage, but announced Monday that no television cameras will be allowed.
Kimmitt also said the military had launched an investigation into interrogation procedures at Abu Ghraib after soldiers accused of mistreating prisoners said they did so at the urging of military intelligence officers.
Seven soldiers, including Sivits, face criminal charges for alleged abuse of Iraqi prisoners. Sivits is the first soldier whose trial date has been set.
Sivits faces a bad conduct court-martial. At least some of those charged will likely face general courts-martial, which can bring more severe punishments — suggesting that he is considered to have played a lesser role in the abuses. The New York Times reports Sivits may have reached a plea agreement.
Newsweek magazine reported in this week's issue that some senior members of Congress have gotten briefings indicating, in the words of one official, that U.S. interrogators were not necessarily "going to stick with the Geneva Conventions" in Iraq or elsewhere.
And The New Yorker reports that within the Pentagon, knowledge of the abuse charges was kept secret even from high-ranking officers who would normally have known about it. The magazine also published a newly released photograph from Abu Ghraib, showing a naked Iraqi man surrounded by U.S. soldiers holding dogs.
The U.S. military units holding and interrogating prisoners in Iraq did not get a specific list of techniques permitted during questioning and were expected to follow long-standing limitations in the Geneva Conventions, a senior Pentagon official said Sunday.
Yet to be determined is whether U.S. soldiers, including those facing courts-martial for abuses committed at the Abu Ghraib prison, were encouraged by commanders to use more aggressive practices intended to elicit more information more quickly from prisoners.
Not applied to Iraqi detainees were the techniques approved by the Pentagon in April 2003 for use at the Guantanamo Bay prison in Cuba, where suspected al Qaeda terrorists are held, according to a senior Pentagon official who discussed the matter on condition of anonymity.
Instead, guards and interrogators in Iraq were expected to follow the Geneva Conventions and other international rules against cruel, inhumane or degrading treatment of prisoners. Army investigations have found that military police were given little or no training in such legal issues.
The techniques approved for use in Cuba were reported in Sunday's Washington Post.
The approved interrogation techniques for Guantanamo Bay included sleep deprivation and exposure to bright lights, but not the forced disrobing of prisoners, the Pentagon official said. No such specific guidelines were drawn up for Iraq, he said.
Last fall, the head of Guantanamo Bay, Maj. Gen. Geoffrey Miller, reviewed prisons in Iraq and suggested that military police serving as prison guards set "the conditions for the successful interrogation and exploitation of internees/detainees." The Army report on the Abu Ghraib abuse criticized that policy, but Miller now has been put in charge of the Baghdad prison.
Miller said last week that MPs' role in intelligence gathering was supposed to be only from "passive" observation, and he blamed Abu Ghraib's leadership at the time for not following military guidelines.
Some Iraqi officials have called for an Iraqi role in the operation of Abu Ghraib. Asked whether the new Iraqi government would assume control of the prison after the transfer of sovereignty, coalition spokesman Dan Senor said Monday that the prison's status will be negotiated after the June 30 handover.