Syrian Foreign Minister Abdel Halim Khaddam told western foreign ministers in private meetings here today that Syria opposed any United Nations role in monitoring the cease-fire in Lebanon.

Western diplomats suggested that the Syrian stand might be a stalling tactic rather than a final position. They expressed the hope that after further meetings with Secretary General Javier Perez de Cuellar on Thursday and Secretary of State George P. Shultz on Friday, Khaddam might agree to some form of U.N. umbrella for the observer force.

British sources said Khaddam told Foreign Secretary Geoffrey Howe this morning that an observer force under U.N. auspices might "put the present partition of Lebanon into granite."

U.N. officials, expressing skepticism with that argument, said Syria wants observers who could be controlled from Damascus and would not report violations back to U.N. headquarters.

Italian Foreign Minister Giulio Andreotti, emerging from his meeting with Khaddam, suggested that Syria might accept some formula under which individual units could be taken from the U.N. Interim Force in Lebanon (UNIFIL), now stationed in the south near the Israeli border, and moved to the Chouf "under their national title" rather than as part of the U.N. force.

Under last Sunday's cease-fire agreement, the formal decision on who the "neutral observers" should be is left to a committee representing the factions involved in the fighting. But in practical terms, Syrian acquiescence is needed.

In his speech to the General Assembly today, Khaddam demanded that the United States, France, Italy and Britain withdraw their 5,400-man peace force from Lebanon, likening it to the "colonialist and crusader expeditions" of the past.

The Syrian foreign minister said that the "direct involvement of the U.S. Marines in the civil war" in support of the Lebanese Army constituted the start of a "process of Vietnamization in Lebanon." He warned that the United States had not learned its lesson in Vietnam, and the outcome in the Middle East would be equally bad for the Americans.

French President Francois Mitterrand, at a U.N. press conference this afternoon, said in response to Khaddam that "any foreign troops that are on the soil of a foreign government can be called colonialist. Syria should think before using that word."

Mitterrand said France would keep trying to win Syrian cooperation and propose that UNIFIL be "enlarged in its mission, geographically and politically, to separate the different factions."

In another speech to the General Assembly today, Egyptian President Hosni Mubarak appealed to Israel to abandon expansionism and coexist with the Palestinians.

"A golden opportunity exists for Israel to attain true peace," he said.