"I conveyed to Clinton my view, both by phone and by letter, that this (threatened military strikes against Yugoslavia) will not work ... We will not let you touch Kosovo," the Russian president said.

The Kremlin has not specified when the discussion took place. However, the White House is quoted as saying that Mr Yeltsin's views were long held and that President Clinton had not spoken recently to his Russian counterpart.

Bridget Kendell reports for BBC News

With the deadline for a peace agreement less than 48 hours away, British and French Foreign Ministers Robin Cook and Hubert Vedrine appealed to the Yugoslav people to accept the Kosovo accord or face a return to the "cycle of internal conflicts and isolation", which have marked the country's recent history.

This was the latest in a series of warnings aimed at persuading Yugoslavia to sign up to a peace deal.

Mr Yeltsin says he will not allow air strikes

On Wednesday, US Defence Secretary William Cohen decided to send more than 50 extra aircraft - including 12 Stealth fighter-bombers - to Europe in case of possible Nato air strikes against Belgrade.

The increased US threat of force was backed up on Thursday by Nato Secretary-General Javier Solana, who warned that Nato would act "very soon" if warring Serbs and ethnic Albanians failed to reach a peace deal at talks in Rambouillet, near Paris.

Deadline looms

The rival delegations - called to the peace table by the Contact Group - have until noon on Saturday to agree a peace deal.

Mark Laity: "NATO is currently at full stretch waiting to see if they need to take action"

The Contact Group wants Belgrade to grant Kosovo substantial autonomy and to allow a 30,000-strong Nato peacekeeping force to police any accord on the ground.

Russia is one of the six Contact Group nations, and while it supports autonomy for Kosovo, it strongly opposes the threat of Nato force against the Serbs, with whom it has traditional ties.

Yugoslav troops are continuing military exercises

The BBC's Moscow correspondent says Russia has always opposed military action against its Serbian allies, but it is not clear what, if anything, the Kremlin could actually do to stop the West if it carried out its threat.

Russia says there can be no Nato deployment in Kosovo without Belgrade's full approval, and Yugoslav President Slobodan Milosevic has ruled out any such deployment.

Mr Milosevic's continuing refusal to accept Nato ground troops in Kosovo as part of an overall settlement is causing growing impatience in Washington, according to a BBC correspondent.

Talks speeding up

However, with the deadline for a peace deal looming, there were reports on Thursday that negotiations at Rambouillet had accelerated - after the Serbian delegation submitted written responses to proposals from US, European Union and Russian mediators.

Serbian President Milan Milutinovic was reported to be returning to the talks on Thursday afternoon "in good faith and fairly optimistic".