The United Nations Secretary General Mr Kofi Annan was horrified at the gruesome murder of American Nick Berg in Iraq, particularly by the public spectacle staged by his killers, his spokesman said on Wednesday.
An Islamist Web site yesterday carried a video clip of the beheading, with a statement saying a group linked to al Qaeda did it out in revenge for the abuse of Iraqis by US troops.
Mr Berg (26), of West Chester, Pennsylvania, was an independent businessman looking for work in communications.
"The secretary general was horrified by the gruesome murder of a civilian hostage in Iraq," chief UN spokesman Mr Fred Eckhard said. "He extends his deepest condolences to the family of the victim and can only imagine how they must be feeling."
Mr Annan was "particularly disturbed" by the use of the killing as a public spectacle, Eckhard said.
But the Secretary General also denounced the killings of civilians and the abuse of prisoners in Iraq.
"The secretary general condemns all killings of innocent civilians in Iraq as he condemns all abuse of prisoners and other violations of international law," Mr Eckhard said.
"Now more than ever, the secretary general once again appeals to all parties to adhere strictly to the fundamental precepts of human rights and principles of international humanitarian law," Mr Eckhard added.