He is expected to press his case at a luncheon with council ambassadors on Friday. And next week more than 40 nations are scheduled to debate the measure in a public meeting, at which time US abuse of prisoners in Iraq and Afghanistan is bound to be mentioned.

"The blanket exemption is wrong. It is of dubious judicial value and I don't think it should be encouraged by the council," Annan told reporters on Thursday.

Annan has opposed the measure in past years but used particularly harsh language this time, noting the human rights scandal in US-run prisons in Iraq.

"I think it would be unfortunate for one to press for such an exemption, given the prisoner abuse in Iraq," he said. "I think in this circumstance it would be unwise to press for an exemption, and it would be even more unwise on the part of the Security Council to grant it."

The United States is investigating abuse of prisoners by the US military in Iraq and Afghanistan.

The Bush administration, for the third year, is seeking to renew a Security Council resolution that would exempt from the court's prosecution military and civilian personnel "related to a UN-authorised operation" such as that in Iraq.

The immunity is extended to all nations not among the 94 countries that have ratified a treaty establishing the court, based in The Hague, Netherlands. The resolution expires by the end of the month.

So far Washington does not have enough support or will barely reach the required nine "yes" votes needed for the resolution to pass in the 15-nation body.

Among the 15 council members, Germany, France, Spain, Brazil, Chile, Benin and Romania, are expected to abstain. But some, like Romania, are reluctant to be responsible for failure of the resolution, if it dies by one vote.

Crucial is whether China abstains. China has criticised the resolution as sending the wrong signal to the world. But diplomats say Beijing is seeking US concessions on Taiwan, although China denies this.

Expected to vote in favour are Russia, Algeria, the Philippines, Pakistan, Angola as well as Britain, one of 94 countries to have ratified the treaty. Its vote is based on Washington's past threat to veto UN peacekeeping missions one by one as it did in 2002, British officials say.

The Bush administration argues that the tribunal, based in The Hague, Netherlands, could be used for politically motivated lawsuits against American soldiers. Supporters say the court's statutes exclude countries with a proper judicial system, like the United States, from prosecution.