The Serbian withdrawal is supposed to be completed within 11 days, under the terms of the agreement signed on Wednesday.

"We made reasonable progress, particularly on the scope and the timing of the Serbian withdrawal," one United States official said.

The Yugoslavs, according to General Clark, suggested that they have their first meeting on Sunday to work out precise details of the Serbian withdrawal.

Close to 400 United Nations troops have now deployed in the mainly Muslim enclave in eastern Bosnia to monitor the cease-fire and the Serbian withdrawal.

The official said an exclusion zone would not mean a total Serbian withdrawal from the Gorazde area.

He is widely thought to have serious reservations about the Serbian withdrawal, and to be convinced that Serbian interests are best served by pressing on with the war.

The Serbian withdrawal marked the first time that their troops have given up any territory they have conquered in the 16-month-old war in Bosnia.

"A Serbian withdrawal?"

Definitive adoption of the plan - and thus any Serbian withdrawal - would be contingent on those talks.

Over the weekend, when military talks on a Serbian withdrawal from Kosovo broke down, NATO threatened to intensify its air attacks.