WASHINGTON -- President Bush paid a high-profile visit to the Pentagon yesterday to praise his beleaguered defense secretary, Donald H. Rumsfeld, who he said is "doing a superb job," and to try to prevent the Iraq prison abuse scandal from further threatening his war goals and his political standing.

More disturbing details of the mistreatment at Abu Ghraib prison are likely to surface today, when the Senate Armed Services Committee is to hear public testimony from Maj. Gen. Antonio M. Taguba, who wrote the Army report that found "sadistic, blatant and wanton criminal abuses" committed by Americans at the prison.

Yesterday at the Pentagon, Bush viewed more than a dozen of the many additional photos and video stills taken by U.S. soldiers at Abu Ghraib that were recently discovered, said his spokesman, Scott McClellan. Bush reacted with "deep disgust and disbelief," McClellan said.

As he seeks to limit political damage from the scandal, the president is weighing the sensitive decision of whether to order the release of the additional photos and video, which have not been made public and which reportedly include graphic sexual acts. Bush has vowed to make the investigation of the Abu Ghraib case transparent, but more images could serve to fuel anger at home and abroad.

Lawmakers are expected to view the new images as early as today. Senate leaders negotiated yesterday with the Pentagon over how the material would be made available to members, in light of concerns about privacy and legality.

A Pentagon spokesman, Larry Di Rita, said hundreds of new images are held on three compact discs at the Pentagon. He called the images "disturbing" and said they include "clearly inappropriate behavior, including some inappropriate behavior of a sexual nature."

The president acknowledged that the photographic images of Iraqi prisoner abuses and humiliations, beamed worldwide, had sullied America's image.

"Those responsible for these abuses," he said, "have caused harm that goes well beyond the walls of a prison. It has given some an excuse to question our cause and to cast doubt on our motives."

Bush said the abuses do not reflect the conduct of the 200,000 Americans who have served in Iraq and should not call into doubt his reasons for going to war.

"We have great respect for the people of Iraq and for all Arab peoples," he said. "Respect for their cultures and for their history and for the contribution they can make to the world. We believe that democracy will allow these gifts to flourish."

The president stood between Vice President Dick Cheney and Rumsfeld in a dining room adjacent to the secretary's office. Before making his formal remarks on Iraq, he turned to Rumsfeld and said he is "courageously leading our nation in the war against terror."

Rumsfeld smiled as Bush continued, "You're doing a superb job. You are a strong secretary of defense, and our nation owes you a debt of gratitude."

Bush sought to buoy Rumsfeld as a growing number of Democrats pushed for him to resign over the prison abuses. Republican Sen. Chuck Hagel of Nebraska questioned Rumsfeld's leadership and whether he could retain the confidence of Americans after the revelations about Abu Ghraib.

The president was hoping to use the trip to the Pentagon, which White House aides said had been long scheduled, as a symbolic gesture to show that he is deeply disturbed by the abuses and determined to hold the guilty accountable.

For days, millions around the world have been digesting pictures showing abuse and humiliation inside the prison on the outskirts of Iraq's capital.

A senior White House official, speaking on condition of anonymity, acknowledged that the scandal had dealt a devastating public relations blow to an administration that had been struggling to quell violence in Iraq and restore order leading up to June 30, when sovereignty is to be transferred to the Iraqis.

The official said Bush is determined to convince Americans and the Middle East that such abuses will never recur.

"This, obviously, was a huge setback," the official said. "It has been pretty damaging in the Arab world as well as at home. But the question for us now is, what we can do to address it?"

An ABC News-Washington Post poll released yesterday indicates that there has been no major erosion in public support for Bush's handling of the scandal. In the survey, 48 percent of Americans said they approved of his response, compared with 35 percent who disapproved. Meanwhile, 69 percent said Rumsfeld should keep his job, compared with 20 percent who said he should step down.