BELGRADE, Yugoslavia (AP) _ U.S. envoy Richard Holbrooke ended a round of crisis talks with Yugoslavia's president early today in a last-ditch effort to reach a diplomatic solution in Kosovo and avoid NATO airstrikes.

Holbrooke travels to the Kosovo capital Pristina today for talks with the main ethnic Albanian leader, Ibrahim Rugova, and then returns for more talks with Yugoslav President Slobodan Milosevic.

The American envoy refused to say whether he had made progress in persuading Milosevic to accept international demands for ending the crackdown in Kosovo.

``There are serious discussions and the situation is serious,'' Holbrooke said after more than six hours of talks that ended well past midnight.

Holbrooke also refused to discuss the Rugova meeting. But a key international demand is a resumption of talks between the ethnic Albanians and the Milosevic-led government.

The ethnic Albanians have refused to meet government officials until Milosevic halts a seven-month crackdown in the province.

Hundreds of people have been killed and tens of thousands have been driven from their homes since Milosevic began the crackdown on Feb. 28 against the ethnic Albanian Kosovo Liberation Army, which is fighting to wrest Kosovo province from Serbia, the main republic of Yugoslavia.

About 90 percent of Kosovo's 2 million inhabitants are ethnic Albanians, and most favor independence.

Milosevic has defied U.N. orders to withdraw substantial forces from the province, maintaining they are needed to prevent new attacks by the KLA.

After the first round of talks Friday, he called NATO threats of airstrikes ``belligerent attempts'' to solve the Kosovo problem, adding that he favors negotiations.

Holbrooke arrived from London, where he met with officials of major powers that are involved in the negotiations. He said that movement toward authorizing the use of force by NATO continues ``in a sustained and intense manner.''

Still, NATO remained divided about the legality and effectiveness of using force against the Serbs.

Italy and Greece, among others, are reluctant to proceed without a mandate from the U.N. Security Council, where Russia and China are opposed.

The chairman of the Russian parliamentary defense committee said Friday that lawmakers may respond to any use of force by recommending Russia abandon its treaty with NATO.

Russia signed an agreement with NATO in May 1997 that sets up a new consultative mechanism and spelled out NATO's intentions as it expands into central and eastern Europe.

In Pristina, cafes were full, with people appearing to make the most of what could be the last few days of relative peace.

``I am not afraid,'' said Jehona Xhaferi, 25, an ethnic Albanian. ``Maybe that's crazy, but I see it as the finishing phase of everything,'' she said, alluding to the months of Kosovo turmoil.

The international demands Holbrooke presented to Milosevic included an immediate end to hostilities and a withdrawal of forces and heavy armaments to the levels they were at before the crackdown.

In addition, Holbrooke was expected to press for the establishment of an international monitoring force to oversee compliance. State Department spokesman James Foley said Holbrooke described discussions so far as ``very intense and tough going.''

The KLA announced a unilateral cease-fire throughout Kosovo starting Friday, a move that will add pressure on Milosevic to reciprocate.

But Serbian media reported at least five KLA breaches of their cease-fire Friday. They said Serbian police and ethnic Albanians loyal to the Serbian government were attacked, but there were no casualties.

The KLA said it was government troops who were on the offensive. In a statement read on state television in neighboring Albania, the rebels claimed villages were being attacked west of Pristina, but added that their troops continued to respect the unilateral cease-fire.

The claims of renewed skirmishes could not be independently verified. Foley said Friday that there had been no new reports of fighting in Kosovo. But he said the absence of fighting did not mean peace.

``While there has been no shooting in the past 24 hours, neither has there been any measurable change in the Serbian deployment of army troops in the field,'' Foley said.