The United States and France issued separate appeals yesterday to Syria to show restraint in intensive fighting that erupted in Lebanon over the weekend and initiated urgent consultations here yesterday in an effort to get a 10-day ceasefire in the war.

French Foreign Minister Louis de Guiringaud postponed his scheduled departure by 24 hours yesterday after receiving reports on the fighting and arranged to meet with Secretary of State Cyrus Vance here today. Yesterday Guiringaud conferred with Saudi Arabia's Foreign Minister Prince Saud Faisal, and other Arab delegates to the U.N. General Assembly.

Lebanese President Elias Sarkis was said to be deeply concerned about the actions of the Syrians troops who make up the bulk of the Arab peacekeeping force stationed in Beirut. The Syrian presence in the past has been a mainstay for the Sarkis government.

The Lebanese war has now become a focal point for international efforts as Egypt and Israel move toward signing a peace treaty as part of the Camp David summit agreements. President Carter issued a preliminary call for an international conference on Lebanon at his press conference last week and a general diplomatic effort to keep the war from spilling over into the Egyptian-Israeli peace process now seems to be under way.

Continuing a marathon work schedule that has been taken him without a break through the Camp David summit, strategic arms limitations talks (SALT) with the Soviets and a still-unresolvedflap over a visa application by Rhodesian Prime Minister Ian Smith, Vance also met with the Saudi foreign minister yesterday.

The Vance-Saud meeting had been scheduled for today but was advanced when Prince Saud decided to fly home last night. He spent the weekend in Cleveland where his uncle and the country's ruler, King Khalid, is to undergo open heart surgery this week.

A source close to the Saudi delegation said the prince's change in plans did not appear to involve any important new developments. The Saudis, after issuing a statement sharply critical of the Camp David agreements, have fallen silent on that subject. U.S. diplomats say that the Saudis have agreed to do nothing to oppose the agreements or to undermine Egyptian President Anwar Sadat.

U.S. officials continued to say that no decision has been reached on granting or refusing visas to Smith and to other members of Rhodesia's biracial Executive Council, established in March with the promise of majority rule for that African country.

Conservative supporters of Smith's government in the U.S. Senate have invited Smith to visit Washington despite a United Nations ban on such travel and the State Department has been weighting the visa request since Sept.20.