The US should close any secret "war on terror" detention facilities abroad and the Guantanamo Bay camp in Cuba, a United Nations report has said.
The committee told the US to end secret detention
The UN Committee against Torture urged the US to ensure no one was detained in any secret facility.
The report followed the first US appearance before the committee since the 11 September 2001 attacks.
A legal spokesman for the US state department said the report contained "factual and legal inaccuracies".
John Bellinger admitted that some "acts of abuse" had occurred in the past, but insisted the US was taking steps to prevent any repeat.
"I think without a doubt our record has improved over the last few years," he told the AFP news agency.
"We take our obligations under the convention seriously."
During the hearing in early May, the US neither confirmed or denied the existence of secret prisons.
The US has been holding hundreds of terror suspects arrested since 11 September at facilities in Iraq, Afghanistan and Cuba. It has been accused of operating secret prisons and transporting some detainees to states which use torture.
The committee also recommended in its 11-page report that the US should:
- Register all those it detains in territories under its jurisdiction
- Eradicate torture and ill-treatment of detainees
- Not send suspects to countries where they face a risk of torture
- Enact a federal crime of torture
- Broaden the definition of acts of psychological torture
'Investigate and disclose'
The committee said it recognised that the 11 September attacks had caused "profound suffering" to the US and welcomed the US statement that officials from all government agencies were prohibited from engaging in torture at all times.
But it told the US its no-comment policy on the secret facilities was "regrettable" and asked for more information.
"The state party should investigate and disclose the existence of any such facilities and the authority under which they have been established and the manner in which detainees are treated," the report said.
Detaining people in such conditions was a violation of the UN Convention against Torture, it said.
It also called on the US to end detentions at the Guantanamo Bay camp and close it, releasing detainees or giving them access to a judicial process.
It called for "immediate measures" to eradicate torture and ill-treatment of detainees by US military personnel "in any territory under its jurisdiction".
It called for an end to interrogation techniques it said constituted torture, such as the use of dogs to scare detainees or sexual humiliation, which the Abu Ghraib prison scandal brought to light.
The recommendations are not binding but the BBC's Imogen Foulkes says the committee's conclusions will not make comfortable reading for the US, with the assertion that secret camps do constitute torture.
US forces have been searching for al-Qaeda suspects in Afghanistan
The US has maintained that it is engaged in a long term war on terror and that some aspects of the convention on torture may not apply.
But the UN committee rejected this, our correspondent says, saying the total ban on torture applies in time of peace, war or armed conflict and anyone violating the convention should be prosecuted.
Human rights groups welcomed the report.
"We hope that the United States will take heed of this report and really begin to rethink and change its policies on a number of practices, including secret prisons, lack of accountability for abuse, and transfer of prisoners to places where they may be tortured," Jennifer Daskal of Human Rights Watch told Reuters news agency.
The committee has asked the US to respond within a year to its recommendations.