The coalition administrator in Iraq has insisted Iraq is benefiting from the occupation despite the publicity given to the abuse of prisoners by US guards.
The US is to keep Abu Ghraib open as a prison
Echoing US President George W Bush, Paul Bremer said the work of troops to rebuild Iraq together with its people showed the "true spirit of America".
But he admitted the abuse had done "enormous damage" to their reputation.
The coalition has revealed it received reports of maltreatment of inmates at Baghdad's Abu Ghraib prison in January.
"Ambassador Bremer was made aware of the charges relating to the humiliation in January 2004," coalition spokesman Dan Senor told reporters.
The US military has confirmed Abu Ghraib will continue to function with tighter controls on staff.
Mr Senor added that he was not sure when Mr Bremer had first seen shocking photographs of the abuses.
The BBC's Adam Brooks reports from Washington that the photographs from the prison have caused palpable dismay and disbelief across America.
President Bush went on US radio on Saturday to say the prison abuse did not "reflect the character" of US soldiers in Iraq as a whole.
In other developments:
- A mortar attack on a US base in the northern city of Mosul on Saturday kills one soldier, the US reports on Sunday
- US troops seize Sayed Amir al-Husseini, head of radical Shia cleric Moqtada Sadr's office in Baghdad's Sadr City district, after a gun battle which leaves at least one militant dead
UK and other coalition troops trade gunfire with Mehdi Army militants loyal to Mr Sadr in Shia areas including Basra, Amara and Karbala
Iraq's former US-appointed human rights minister, Abdel Basset Turki, has said Mr Bremer knew about the alleged abuses earlier than the coalition has admitted/
Mr Turki said he highlighted abuses last November in a conversation with Mr Bremer.
Bremer has been seeking to woo Iraqi opinion
"He listened but there was no answer," Mr Turki, who quit a month ago over the bloody US siege of the city of Falluja, told AFP news agency.
The International Red Cross said earlier it had repeatedly asked the US authorities to take action over alleged abuses at Abu Ghraib months before CBS television reported it ten days ago.
US Congressman Steve Buyer, who served as a legal adviser during the 1991 Gulf War, has said that the Pentagon rejected his offer to go to Iraq last year to give advice on handling prisoners.
He said his request had been rejected because of his high profile, although, he said, there was widespread support within the military for the idea.
The British government, meanwhile, has confirmed it received a Red Cross report on separate alleged abuses by UK troops against Iraqi prisoners in February.
A US guard charged with abuses at Abu Ghraib has contradicted official claims that prisoners were abused only by rogue elements.
Sabrina D Harman, has told the Washington Post that military police in the jail were tasked with "making it hell so they [the prisoners] would talk".
In an e-mail sent from Baghdad, she said she had not read the Geneva Convention on treating prisoners of war until after being charged.
Local leaders in Iraq's largely Sunni al-Anbar Province, where Falluja is situated, have urged the coalition to release all non-criminal prisoners as a gesture of good will.
"We need a measure that is as big as the affair that has happened - it needs to reflect the size of the problem," said representative Mamouon Sami Rasheed at talks with Mr Bremer in Baghdad.