US President George Bush has dismissed as "absurd" an Amnesty International report that said the US was setting back the cause of human rights.
George Bush said the US "promotes freedom"
The human rights group described the US Guantanamo Bay detention camp in Cuba as "the gulag of our time".
There have been allegations that guards at the camp had desecrated the Koran, prompting protests in Muslim countries.
But Mr Bush said on Tuesday: "The United States is a country that promotes freedom around the world."
"I'm aware of the Amnesty International report and it's absurd, it's an absurd allegation," the president said during a press conference in the Rose Garden of the White House.
Mr Bush said that accusations against Americans were "fully investigated in a transparent way".
"In terms of the detainees, we've had thousands of people detained, we've investigated every single complaint," he said.
The Amnesty report has already provoked a robust reaction from the US top military officer General Richard Myers and Vice President Dick Cheney.
"I think the fact of the matter is the United States has done more to advance the cause of freedom, has liberated more people from tyranny over the course of the 20th century and up to the present day than any other nation in the history of the world," said the vice president.
The report from the London-based human rights group followed allegations made by former detainees at Guantanamo Bay and other US facilities across the world.
Mr Bush said its accusations therefore stemmed from "people who hate America, people that have been trained in some instances to disassemble, that means not tell the truth".
But Amnesty hit back. Executive director William Schulz said: "What is 'absurd' is President Bush's attempt to deny the deliberate policies of his administration."
"What is 'absurd' and indeed outrageous is the Bush administration's failure to undertake a full independent investigation."