The Clinton administration and the NATO alliance gave strong indications yesterday that punishing military action against Yugoslavia is imminent, perhaps within a week, because of continuing violence by Serbian forces against the Albanian ethnic majority in Kosovo province.

U.S. officials and diplomats here and in Brussels said the discovery this week of the bodies of dozens of ethnic Albanians, including women and children, who had been massacred apparently by Serb forces has blown away the last vestiges within the alliance of resistance to military strikes. Russia opposes the use of force, but there are no longer any major holdouts within NATO, diplomats and U.S. officials said.

President Clinton's senior foreign policy advisers met yesterday to discuss the atrocities against civilians and invited all members of the U.S. Senate to a classified briefing this afternoon on NATO's plans.

After conferring with Secretary of State Madeleine K. Albright, British Foreign Secretary Robin Cook said Britain will press for the expedited release, probably on Monday, of a report by Secretary General Kofi Annan on Serb compliance with a Security Council resolution passed a week ago demanding the withdrawal of Serb security forces from Kosovo.

After four meetings in Brussels yesterday, the NATO allies agreed that Annan's report will be decisive in determining whether airstrikes would begin. Unless Annan reports that Yugoslav President Slobodan Milosevic is withdrawing his forces, an extensive military campaign is likely within a few days, a NATO official said.

"Obviously if Annan's report is negative, it will be the basis for a decision by NATO," a NATO official said. "We are not at the stage of action yet, it would take a few days, but we have incontrovertible evidence now that Milosevic's attacks have gone beyond any legitimate actions, destroying villages, committing atrocities against old men -- this is a form of war against his own people."

"The direction is clear, given where Milosevic is. There may be some minor adjustments in the timing," an administration official said.

State Department spokesman James Foley and other U.S. officials also said yesterday that while the Serbs have pulled back some security forces, as they announced Monday they would do, the departing forces have been replaced by newly arrived units, resulting in no net reduction in the Serb presence.

NATO's military planning is complete, officials said. Several members have offered to contribute aircraft and troops, including a commitment by Germany to provide more than a dozen Tornado jet attack aircraft. According to one U.S. source, the strike plan calls for a strong initial series of raids by NATO warplanes, followed by a brief pause to give Milosevic time to reconsider, followed by sustained strikes aimed at crippling his armed forces if he fails to change course. NATO officials said it may also be necessary to deploy some ground troops in Kosovo to police the cease-fire the airstrikes would be designed to bring about.

Milosevic sent thousands of Yugoslav army troops and Serbian security police into Kosovo earlier this year to put down a separatist insurgency by ethnic Albanian rebels. The United States and its allies, while wanting to stop Milosevic from pursuing the nationalistic violence in Kosovo that he promoted in Bosnia, were reluctant to intervene in an internal Yugoslav matter, in which the Western allies do not support Kosovar aspirations for independence. Kosovo is a province of the republic of Serbia, which is the dominant partner of Yugoslavia.

But with about 50,000 displaced civilians camped without shelter in the hills as the Balkan winter approaches -- some of the estimated 300,000 people who have fled their homes to escape fighting -- and Milosevic apparently defying the U.N. demand for a troop pullback and a negotiated settlement, pressure is mounting for some strong action by the Western alliance.

Several key members of the Senate, including John McCain (R-Ariz.), Mitch McConnell (R-Ky.), Gordon Smith (R-Ore.) and Dianne Feinstein (D-Calif.), made strong statements last week saying they would support military action against Milosevic and the Serbs.

Yugoslavia announced Monday that it had crushed the ethnic Albanian Kosovo Liberation Army (KLA) and was ending military operations. But Foley said yesterday that fighting was continuing, and Yugoslav Foreign Minister Zivadin Jovanovic said the army plans to remain in the province.

"The government has declared that the terrorists have been neutralized, so there can be a partial withdrawal of the security forces," Jovanovic told Washington Post editors and reporters. "The regular police forces maintaining law and order will stay. Special antiterrorist forces will go back to their barracks and stay on alert. The army will stay to guard the border" with Albania, he said.

Jovanovic did not deny that atrocities had occurred -- most of the victims were found with bullet wounds in the backs of their heads -- but he insisted that "there is no indiscriminate killing of civilians. There is only a struggle against terrorism. Sometimes this leads to the abuse of civilians."

He said ethnic Albanian civilians were turning in their weapons and "things are moving positively in all aspects. There is nothing that could be solved or helped by [NATO] rockets."

But Foley noted that "it's been six days" since the Security Council resolution was adopted and "we don't see that Milosevic has gotten the message or reversed course."