In a report for the United Nations' Committee against Torture, the London-based human rights group also alleged abuses within the US domestic law enforcement system, including use of excessive force by police and degrading conditions of isolation for inmates in high security prisons.

"Evidence continues to emerge of widespread torture and other cruel, inhumane or degrading treatment of detainees held in US custody," Amnesty said in its 47-page report.

It said that while Washington has sought to blame abuses that have recently come to light on "aberrant soldiers and lack of oversight," much ill-treatment stemmed from officially sanctioned interrogation procedures and techniques.

"The US government is not only failing to take steps to eradicate torture, it is actually creating a climate in which torture and other ill-treatment can flourish," said Amnesty International USA Senior Deputy Director-General Curt Goering.

The UN committee, whose experts carry out periodic reviews of countries signatory to the UN Convention against Torture, is scheduled to begin consideration of the United States on Friday. The last US review was in 2000.