Although in May and July the State Department reprimanded the Serbs for trying to impose their will on other Yugoslav republics, it always accompanied those warnings by cautioning the other republics against unilaterally pulling away from the Serbian-dominated central Government.

Such a course would have eased international pressure to tighten United Nations sanctions against Yugoslavia, whose Serbian-dominated Government is seen by the world as the sponsor of the Bosnian Serbs.

In Belgrade, the Serbian-dominated Government denounced the decision on recognition as "contrary to the sovereign rights of Yugoslavia."

The Serbian-dominated Government in Belgrade is confident that the United Nations, whose membership includes countries threatened by political disintegration, will give Serbia a more sympatheic hearing than the European Community has granted to date.

American, British and French officials said the meetings were expected to authorize the use of warships in the Adriatic Sea to enforce the United Nations embargo against the Serbian-dominated Government of Yugoslavia but would refrain from overt intervention in the conflict.

Secretary of State James A. Baker 3d is considering a break in American relations with the Serbian-dominated Government of Yugoslavia and the closing of the embassy in Belgrade, Administration officials said today.

Governments of nine West European countries agreed on Friday to ask the European Community's defense arm to recommend measures to enforce the United Nations embargo against the Serbian-dominated Government of Yugoslavia.

Diplomats said this was partly because the United States did not want to confer legitimacy on the Serbian-dominated Government in Belgrade, which occupies the former Yugoslavia's United Nations seat, by allowing it to speak.

New U.N. Sanctions The vote to reject the peace plan set off new sanctions against what remains of Yugoslavia, whose Serbian-dominated Government supports the Bosnian Serbs.

The Security Council is considering a resolution urging Yugoslavia's suspension from this year's Assembly as a way of putting pressure on the Serbian-dominated Government in Belgrade to do more to promote peace in Bosnia and Herzegovina.