Senior American officials testified before the UN Committee Against Torture in Geneva in May for the first time since the 11 September 2001 attacks.
The committee recommended the closure of Guantanamo Bay
The committee has now delivered a report on its conclusions.
It calls on the US to close any secret "war on terror" detention facilities abroad and the Guantanamo Bay camp in Cuba.
BBC News examines the review process and conclusions reached.
Why did the US have to appear before the panel?
The UN Committee Against Torture is the watchdog for the 1987 treaty at the centre of international human rights law, the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment.
The 141 states party to the convention must periodically submit reports and appear before the UN to show that they are following the rules.
Washington was last reviewed by the committee in 2000.
How did the review process work?
Thirty senior officials from the US State, Defense, Justice and Homeland Security departments testified before the 10-member expert panel in Geneva on Friday 5 May and Monday 8 May.
The committee had 59 questions for the US, 53 of which related to the "war on terror".
The committee then addressed its recommendations and concerns to the US in a concluding report.
Which issues did the UN address?
Officials were asked to provide a list of all secret detention centres, nationalities and numbers of those being held and the reasons for their detention.
It wanted to know what measures the US had taken in the wake of the Abu Ghraib prisoner abuse scandal. Methods of interrogating prisoners and rules governing their use were also raised.
The committee also asked for details of detainees taken abroad to third countries, in a process known as extraordinary rendition.
It also examined Washington's interpretation of the absolute ban on torture.
What did the US say?
The delegation said that US officials were forbidden from engaging in torture under any circumstances.
Delegation officials described abuses carried out at Iraq's Abu Ghraib jail as "indefensible", but said more than 250 people had been held accountable and Washington had taken action to tackle ill-treatment of detainees.
The delegation did not answer all the committee's questions. It neither confirmed nor denied the existence of secret detention camps, maintaining a no-comment policy on the issue.
State Department legal adviser John Bellinger said abuse of detainees was not systemic. "Allegations about US military or intelligence activities have become so hyperbolic as to be absurd," he said.
What did the committee's report conclude?
The 11-page report contained several recommendations for the US.
The committee told Washington the convention on torture applied at all times, "in war, peace or armed conflict".
It said detaining people in secret camps violated the convention, calling on the US to investigate and close any secret "war on terror" detention facilities abroad.
It recommended the closure of the Guantanamo Bay facility. It said the US should register all individuals held in detention facilities under its jurisdiction and set out the grounds for holding them.
The committee also said that "immediate measures" were needed to eradicate torture and ill-treatment of detainees by US military personnel.
It urged the US to rescind interrogation techniques it said constituted torture, such as the use of dogs to scare detainees and sexual humiliation.
It said the US should cease the rendition of suspects to states where they face the risk of torture.
What happens next?
The committee has asked the US to respond within a year to several of its concerns and recommendations.
The US is obliged by the UN convention to implement the committee's recommendations, but there is no enforcement mechanism.
Human rights campaigners said the hearings had huge significance.
Human Rights Watch said it was the first time the US was held accountable for its record on torture with regard to some of the practices implemented after 9/11.