While the world already has been horrified by pictures of American soldiers abusing Iraqi prisoners, the Pentagon warns there are many more photos and videos that have not been disclosed.

They show "acts that can only be described as blatantly sadistic, cruel and inhuman," embattled Defence Secretary Donald Rumsfeld told Congress.

From the White House to Capitol Hill, policy-makers are worried that the United States faces lasting damage abroad particularly in the Middle East from the pictures of naked Arab men being tortured and humiliated by American soldiers, the same forces sent to Iraq to liberate the country from Saddam Hussein's torture and repression.

Analysts describe the pictures as great recruiting tools for al-Qaeda and other extremist groups and said they undermine America's claims to a moral high ground. Rumsfeld said the impact was "radioactive."

Bush, in his weekly radio address Saturday, said, "They are a stain on our country's honor and reputation." He said the abuses were the work of a few and do not reflect the overall character of the 200,000 members of the US military who have served in Iraq in the past year.

Six months from the November elections, Iraq weighs heavily on the president.

April was the deadliest month yet for American soldiers in Iraq and May is off to a bloody start.

On the diplomatic front, the administration does not know who will take power in Iraq from the United States in a June 30 handover.

Costs are soaring. The administration has sent Congress an unexpected $25 billion request for Iraq and Afghanistan.

Day after day, the extraordinary apologies from the president and his top deputies dominated the news.

Pollsters and presidential experts are scratching their heads over how the prisoner scandal will affect Bush's re-election hopes.