UNITED NATIONS (AP) _ Western and Muslim nations squared off Tuesday night in a Security Council debate about exempting the Bosnian government from the U.N. arms embargo.

Muslim nations argued that U.N. embargo barring arms sales to all parties fighting in the former Yugoslavia has failed.

But Britain, Russia and France - Security Council members with veto power - said lifting the embargo would undermine peace.

The debate, expected to continue Wednesday, was requested by Pakistan on a General Assembly resolution that had a strategic defeat last week.

The assembly approved a non-binding measure that merely encourages the Security Council to exempt the Bosnian government from the arms embargo - but 10 of the 15 Security Council nations abstained.

Although the speeches Tuesday were not directed at a U.S.-sponsored resolution that also calls for lifting the embargo, the debate would determine how far Washington would push to exempt the Muslim-led government from the embargo, said an American official speaking on condition of anonymity.

A resolution introduced Friday by U.S. Ambassador Madeleine Albright would lift the embargo in six months if the Bosnian Serbs don't sign a proposed peace treaty already agreed to by Bosnia's Muslim-Croat federation.

The United States needs at least nine 'yes' votes on the Security Council to get its arms-lifting resolution passed, and prominent diplomats say that is extremely unlikely. One veto would kill it.

The speeches Tuesday began with France, Russia and Britain arguing against lifting the embargo.

''None of us want to lose the gains of the past year,'' said British Ambassador Sir David Hannay. ''The priority now is to make early and visible progress toward settlements in Bosnia and Croatia.''

However, Turkish Ambassador Engin Ahmed Ansay said that Bosnia's Muslim-led government had been patient enough.

''All the commitments and promises made to the government and people of Bosnia-Herzegovina remain unfulfilled,'' he said. ''The defiance of international law by the aggressors remain unchallenged.''

In Bosnia, meanwhile, government forces have been making significant military advances in the 31-month-old war that has left 200,000 dead or missing. News reports say the government is receiving a steady supply of arms and ammunition despite the embargo.