Top U.S. generals in Iraq are to appear before a U.S. Senate panel in Washington Wednesday to answer questions about the Iraqi prisoner abuse scandal.

Testifying publicly before the Senate Armed Services Committee will be General John Abizaid, the top commander of U.S. forces in the Middle East, Lieutenant General Ricardo Sanchez, the senior U.S. officer in Iraq, and Major General Geoffrey Miller, who recently was assigned to oversee management of Iraq's prisons in the wake of the scandal.

Lawmakers want to know how high in the military chain of command the mistreatment of Iraqi prisoners was known, and whether the abuse was ordered by military officials.

Photographs of prisoners subjected to sexual humiliation and other brutality at the hands of U.S. soldiers have prompted international outrage.

The top Democrat on the Senate Foreign Relations Committee, Senator Joe Biden, says President Bush should seek Iraqis' permission to tear down the Abu Ghraib prison where the abuse occurred, and replace it with something the Iraqis want, like a school or a hospital.

"The president, I think, has to make a gesture as dramatic and consequential as the symbolic damage done when in fact the prison scandal broke," says Mr. Biden. Mr. Biden made his comments Tuesday before the Foreign Relations Committee.

Meanwhile, some controversy has arisen over the handling of Wednesday's Armed Services Committee hearing.

In an unusual development, the Republican chairman of the panel, Senator John Warner, is coming under criticism from the chairman of the House Armed Services Committee, Congressman Duncan Hunter, who is also a Republican.

Congressman Hunter said, in his words, it is a "mistake" to pull out operational leaders in Iraq and deprive U.S. troops of their leadership so that, as he put it, "the Senate can have a lot of publicity."

Senator Warner did not directly respond to Mr. Hunter's comments. But he noted he asked Defense Secretary Donald Rumsfeld if the witnesses could appear by video teleconference. He said the Pentagon made them available in person.