LONDON: United States must open itself to an independent probe into the use of drone strikes or should allow the United Nations to step in and investigate such issues, a leading human rights barrister said.

According to the report published in British newspaper The Independent, Ben Emmerson, UN Special Rapporteur on Human Rights and Counter-Terrorism, said the US is facing mounting global pressure over its use of UAVs and he is preparing a report for the next session of the Human Rights Council in March.

He insisted the issue will "remain at the top of the UN political agenda until some consensus and transparency has been achieved".

According to the paper, Emmerson said it was time for the US to open itself up to scrutiny as to the legality of such attacks.

He said that while it remains nigh on impossible for observers to establish the truth on the ground in many of areas, each strike is visually recorded and videos could be passed to independent assessors.

"We can't make a decision on whether it is lawful or unlawful if we do not have the data. The recommendation I have made is that users of targeted killing technology should be required to subject themselves, in the case of each and every death, to impartial investigation," the paper quoted Emmerson, as saying.

"If they do not establish a mechanism to do so, it will be my recommendation that the UN should put the mechanisms in place through the Human Rights Council, the General Assembly and the Office of the High Commissioner", he added.