A detachment of French troops is scheduled to arrive here early today to join the U.N. peacekeeping force in southern Lebanon, the first contingent to enter the area from the Lebanese side of the border.

It is not clear, however, whether they will be able to deploy into the border region right away because of unresolved questions about Palestinian troops soll holding territory between Beirut and the border area now occupied by Israel.

The Palestinian news agency WAFA reported yesterday that Yasser Arafat, chairman of the Palestine Liberation Organization, met with French Ambassador Argod.

Sources said the talks dealt with the PLO's terms for cooperating in the deployment of the French troops through territory held by the Palestinians. The PLO is said to be asking assurances that the U.N. force is going into the border area to preside over the departure of the Israelis and the return of the inhabitants.

The Lebanese are reported to be extremely sensitive to anything that calls into question the sovereignty of the Beirut government over all of Lebanon's territory. But it is the Palestinians, not the Lebanese, whose cooperation will be required if the U.N. force is to move unhindered from Beirut into the south.

The operation in Lebanon represents the first French participation in a U.N. emergency force.

France was the colonial power in Lebanon before independence in 1943, and had often flirted with the idea of sending troops or other forms of assistance here during previous crises.

The French stationed a warship off the coast during the landing of the U.S. Marines in 1958 and the U.S. refusal to accept French participation led to a smoldering resentment against Washington by President Charles de Gaulle.