President Clinton said yesterday that President Slobodan Milosevic may be seeking to steal victory from the opposition and cautioned him to respect the will of the Yugoslav people.
"It certainly appears from a distance that they got a free election and somebody is trying to steal it away from them," Mr Clinton said, pledging US support for the opposition in its standoff with Mr Milosevic.
"The government's official election commission has no credibility whatever," Mr Clinton told reporters at the White House.
"There were no opposition party members on it. There were no independent observers that have monitored its work.
"And the opposition believes it clearly got over 50 per cent, and at least another NGO (non-governmental organisation) and other independent observers believe it did too."
The comments were the first by Mr Clinton since Yugoslavia's federal election commission announced on Tuesday the first official results from Sunday's election, declaring that opposition candidate Dr Vojislav Kostunica won 48.2 per cent of the vote to Mr Milosevic's 40.2 per cent.
A candidate needs more than 50 per cent of the vote to be declared the outright winner and avoid a run-off.
Independent observers and the Democratic Opposition of Serbia coalition which backed Dr Kostunica said their tallies gave the opposition candidate 56 per cent of the vote.
The US Secretary of State, Ms Madeleine Albright, urged all nations, particularly Serbia's traditional ally Russia, to accept that Mr Milosevic had lost and support the Yugoslav people's choice.
"We have had some differences but those may be coming to an end," Ms Albright said, referring to Moscow's vehement opposition to last year's NATO bombing campaign during the Kosovo crisis.
"The people of Serbia have spoken and I think it is very important for everyone to hear what they have said," she told the House International Relations Committee.
Other Western leaders accused Mr Milosevic of fraud but criticism was tempered by concern about a potential flare-up of violence in the unstable region.
President Jacques Chirac of France, which holds the rotating EU presidency, condemned "current manipulations to steal victory from the Serb people", while Chancellor Gerhard Schroder of Germany said a resolution to the crisis must be found with "no increase in violence".
Mr Clinton argued that the Yugoslav opposition parties should take the lead in deciding how to react to the latest move by the Belgrade authorities.
Europe and the US should support the expressed will of the Serbian people, he said. "Whatever we do, I think, should be consistent with the wishes of the majority of the people there."
A senior Clinton administration official said the US was in close consultation with its EU allies amid calls for a lifting of sanctions imposed on Belgrade.
Mr Clinton said on Tuesday sanctions would be lifted if Mr Milosovic stepped down and the opposition was allowed to take power.
NATO is taking pains to keep a low profile on the Yugoslav elections to avoid providing Mr Milosevic with a pretext to declare a state of emergency, an alliance official said yesterday.
The NATO Secretary General, Mr George Robertson, back in Brussels yesterday after having cut short a Caucasus tour to return to follow developments, said: "The democratisation of the Federal Republic of Yugoslavia is in the hands of the Yugoslav people."
The US and Britain also denied that military manoeuvres they are currently carrying out in the region were intended as a show of force to Belgrade.
Croatian-US manoeuvres began on Tuesday on the southern Adriatic coast, and Britain acknowledged this week it had 15 warships off the coast of the former Yugoslavia, but denied they were there to "send a message".
The UN Secretary-General, Mr Kofi Annan, said voters in Yugoslavia had shown they wanted change and he hoped they would get a democratic government.
Mr Annan said he also hoped "that the problems of the region will be addressed in the spirit of co-operation rather than confrontation".