Kofi Annan, the United Nations secretary-general, is writing a report this weekend on whether Serbia is complying with the UN resolution demanding an end to its offensive in the province. But sources say Mr Annan is unlikely to condemn Serbia outright.
Without a clear signal from the UN, some Nato governments will feel they do not have legal authority to bomb Serbia, even with proof that its forces are massacring civilians, including young children.
While awaiting Mr Annan's report, Tony Blair and other Western leaders maintained a verbal onslaught against President Slobodan Milosevic, warning that he faced a "military penalty" if he did not halt his attacks on Albanian civilians in Kosovo.
President Bill Clinton said Nato was prepared for military strikes "We have to be very, very strong here," he told reporters. "We need to stop the violence, get a negotiated settlement and work our way through this.
"I believe that our allies in Europe are with us, and I think that we all understand, and we hope he [Milosevic] got the message."
At a six-nation Contact Group meeting in London, the United States tabled a draft political settlement for Kosovo that would give more autonomy to the ethnic Albanians. An earlier US proposal was denounced as a sell- out by the Albanians, who are seeking full independence from Serbia.
Britain also announced last night that it was sending an additional four RAF Harrier ground-attack aircraft to a Nato base in southern Italy, where they will join the force that Nato has assembled for potential war in the Balkans.
Britain, Canada, Norway, Germany, the Netherlands, Spain and Portugal have announced plans to send warplanes to join the American forces already on stand-by.
Mr Blair said the West would force Mr Milosevic to "stop committing atrocities and barbarism within Kosovo". The Prime Minister added: "This is a humanitarian disaster. I believe it will only be stopped if Milosevic gets the clearest possible message, which is an unmixed message, namely, if you carry on doing this you will face a military penalty."
George Robertson, Secretary of State for Defence, told the Labour Party conference in Blackpool that Nato military planning for air strikes on Serbia was "almost complete".
Addressing Serbia's leader directly from the podium, he said: "Stop the violence, the cold-blooded murders of innocent civilians, return your sinister troops to barracks, let the people return to their homes in safety - and start negotiating a political settlement. The clock is ticking."
The situation in Kosovo and the escalating military tension led yesterday to the cancellation of the international football between England and Yugoslavia scheduled for 18 November at Wembley.
The Football Association denied the decision had been taken because of political pressure. David Davies, the FA's director of public affairs, said: "The decision to cancel the game is ours." Going ahead with the match in the current circumstances would be "insensitive in the extreme and wrong", he said.
Behind the scenes, divisions in the international community over action against Serbia seemed wider than ever last night. Russia's new prime minister, Yevgeny Primakov, repeated that Moscow remains strongly opposed to force, while the Russian parliament said Nato action against Belgrade would be "an illegal act of aggression". The state Duma said such action might mean Russia tearing up all existing agreements with Nato.
At the heart of the splits at the UN is the widespread fear that outside intervention in Kosovo would constitute a legal minefield, as Kosovo is incontestably - whatever its inhabitants think - a part of Serbia. Intervention, therefore, would constitute interference in the affairs of a sovereign state, and pose a dilemma for many countries facing separatist rebellions.
In the conflict in Bosnia in 1995, Nato jets ended the Serb siege of Sarajevo by strafing their positions around the capital. But Bosnia was an independent state, and Nato's action came at the express request of its internationally recognised government.
Seeking to play on these divisions, and head off the threatened attack, Mr Milosevic last night invited Mr Annan to visit Serbia to investigate the alleged atrocities for himself.
Belgrade insists that the 36 Kosovo Albanian civilians massacred in three separate incidents in Kosovo were all victims of the Albanians themselves.
By partially withdrawing forces responsible for the massacre of civilians and the crackdown on insurgents from the Kosovo Liberation Army, Mr Milosevic may frustrate attempts to punish his armed forces with Nato air strikes.Reuse content