President George W Bush has denounced the mistreatment of Iraqi inmates by US soldiers as "abhorrent".
Photos of the treatment of Iraqi prisoners have shocked the world
In interviews with Arabic TV channels, he insisted that the abuse was not typical and that those responsible would be punished.
Earlier, the new US military chief of prisons in Iraq apologised for the "illegal or unauthorised" actions.
Photographs of naked Iraqi prisoners in humiliating poses next to laughing US soldiers have shocked the world.
In interviews for US-funded al-Hurra network and the al-Arabiya satellite channel, President Bush said: "People in Iraq must understand that I view those practices as abhorrent.
"They must also understand that what took place in that prison does not represent the America that I know."
Mr Bush said that, in democracies, mistakes were made but: "There will be investigations, people will be brought to justice."
He rejected comparisons of the US treatment of detainees in Abu Ghraib prison to the practices under the Saddam Hussein regime, when the jail became notorious for the torture carried out there.
"A dictator wouldn't be answering questions about this," he told al-Arabiya.
The president revealed that the first time he saw the photographs of the abuse was when they appeared on US television late last month.
But he said US government officials had been investigating allegations of mistreatment since they were first made in January.
The US Defence Secretary Donald Rumsfeld will testify in an open session on Friday on the abuse of Iraqi prisoners, Senate Armed Services Committee Chairman John
Warner said on Wednesday.
Mr Warner said Mr Rumsfeld would appear for two hours before the committee in open session, then will hold a closed briefing for the full Senate.
President Bush said in his TV interviews that the US was not seeking to impose double standards - criticising other countries for human rights abuses while its troops mistreated prisoners in military jails.
A photograph showing a dead Iraqi man alleged to have been taken at the Abu Ghraib jail has emerged. You may find this image disturbing.
"We will do to ourselves what we expect of others," he said.
President Bush was not asked to apologise, nor did he offer an apology during either 10-minute interview.
But White House spokesman Scott McClellan later told reporters that Mr Bush was "sorry for what occurred" in the prison.
National Security Adviser Condoleezza Rice earlier expressed "the United States' deep sorrow over the US troops' abuses against the Iraqi prisoners".
But the BBC's Paul Wood in Cairo says the lack of an explicit apology from Mr Bush himself angered many people there, as well as Mr Bush's refusal to determination to see the abuses as anything other than an aberration.
Our correspondent says many in Egypt believe the abuse is systematic, and reveals the true face of the occupiers in Iraq.
Mr Bush laughed off suggestions that US military action in Iraq was inviting new attacks from al-Qaeda, saying that Osama Bin Laden's group had declared war in its attacks of 11 September 2001 and that that conflict was still being fought.
He also said that he hoped Iraqi people would "deal with" the radical cleric Moqtada Sadr, though he added that US forces would help to fight his militias, which are pushing for control of some of Iraq's holy cities.
An internal Pentagon report catalogued evidence of "sadistic, blatant and wanton criminal abuses of Iraqi prisoners" by US forces.
A man told the BBC he was the prisoner featured in one of the photographs, naked except for a hood covering his head, with his hands on his head while a smiling female soldier pointed at his genitals.
Haider Abed said: "After two hours of beatings they took off my hood and forced me to perform sexual acts in front of a female soldier. After all the beatings, I didn't have the strength to resist."
Another graphic photograph apparently of a dead Iraqi man covered by bags of ice at the Abu Ghraib prison has also been published by US media. Officials have not commented on its authenticity.
US military officials say there have been 25 deaths of prisoners in Iraq and Afghanistan since December 2002, two of which have been classified as murder.
Criminal charges have been filed against six soldiers in relation to the abuse shown in the photos, while six senior officers have been reprimanded.
Major General Geoffrey Miller, the new US military chief of prisons in Iraq, said some interrogation techniques used on Iraqi inmates would be halted and others toned down as a result of the scandal.
He apologised for the "small number of soldiers who committed illegal or unauthorised acts" and promised it would not happen again.