The US has not appeared before the panel since 9/11

The officials were answering further questions from the UN Committee Against Torture in Geneva amid concerns about US actions in its "war on terror".

The delegation repeated that US officials were forbidden from engaging in torture under any circumstances.

Rights groups accuse the US of flouting the UN Convention against Torture.

They say the US allows the torture and inhumane treatment of foreign terror suspects at their detention centres around the world, including Afghanistan, Iraq and Guantanamo Bay, Cuba.

Ten legal experts have been cross-examining the US team on a series of issues since last week.

The US delegation, which last Friday began its account by stressing that it considers the use of torture as wrong, said Washington had taken action to tackle ill-treatment of detainees.

COMMITTEE KEY QUESTIONS Interpretation: How does Washington interpret the absolute ban on torture Interrogation practices: What rules and methods does the US employ Secret prisons: Why has the US established secret prisons Responsibility: Does the US take responsibility for torture committed by agents overseas Abu Ghraib: What measures have been taken to identify and remedy problems Investigation: Has there been an independent investigation into whether defence officials authorised torture Read the questions in full: UN Committee Against Torture: Questions to US in full (48K) Most computers will open PDF documents automatically, but you may need to download Adobe Acrobat Reader. Download the reader here Q&A: US torture hearings

"To date there have been 103 courts martial, 89 service members were convicted which represents an 86% conviction rate," US Deputy Assistant Secretary of Defence Charles Stimson said.

He said these numbers contrasted with those from Human Rights Watch which said there had only been 54 convictions.

State Department legal adviser John Bellinger said most of the "regrettable incidents or allegations" emerged several years ago.

"I am not trying to minimise their significance in any way but to emphasise that without question our record has improved," he said.

"We now have more rigorous laws, more rigorous procedures, more rigorous training and more rigorous monitoring mechanisms."

'Waterboarding'

The BBC's Imogen Foulkes in Geneva says members of the US delegation have all said the same thing - that American officials are forbidden from engaging in torture under any circumstances.

The problem, she says, is that the US has not been specific about what it defines as torture.

The UN committee asked about the practice of waterboarding, described by human rights groups as mock drowning.

The US officials replied that this was prohibited in the new army field manual.

Following Monday's session, the committee will now prepare its recommendations expected to be released on 19 May.

The US is obliged by the UN convention against torture to implement the recommendations, although there is no enforcement mechanism.