Diplomats are warning that the future of the United Nations peacekeeping mission in Bosnia is threatened by a dispute over the world's first permanent war crimes tribunal.

There's nothing on the table that looks like common ground at this moment

UK Ambassador Jeremy Greenstock

The United States has said it could pull out of the force in Bosnia if American peacekeepers are not granted immunity from the International Criminal Court (ICC), which is due to be formally established in the Netherlands next week.

The court is to deal with alleged genocide, war crimes and human rights abuses around the world.

Last week, the deadline for renewing the mandate for the Bosnia peacekeeping operation was extended by nine days to allow discussions to continue, in the hope of reaching a compromise before the court starts work.

The US cannot veto the continuation of the peacekeeping operation, but its withdrawal from the force could have serious consequences.

The country provides 3,100 peacekeepers to the 17,000- strong force. Officials say all of the US members carry out necessary work, and would need to replaced if they were removed.

At present it is unclear where the force would look to find replacements if the US did decide to pull out.

Veto threat

The US has not ratified the Rome Treaty which brings the ICC into being, but countries which have are bound by law not to back anything which undermines the powers of the court.

This means in theory they could not approve the exemption of US peacekeepers.

The US wants the United Nations to agree exemption

Washington says it is worried about politically-motivated prosecutions against its citizens.

It insists the issue should be resolved before UN mandate in Bosnia is renewed, scheduled for this weekend.

Britain's UN ambassador Sir Jeremy Greenstock says the Bosnia mission could fall victim to the stalemate.

"It's just a question of how hard the parties to this issue want to play it, but it is not to be entirely dismissed that an individual peacekeeping operation may be held hostage to a much wider and deeper question," he said.