Israeli forces began the second phase of their withdrawal from southern Lebanon yesterday, and their commander said that the pullback can be completed in a month if all U.N. peacekeeping troops are in place by then.

Israeli tanks and troops pulled out of the battered village of Taiba during the night, leaving three armored personnel carriers at a position overlooking the Litani River to greet the Nepalese U.N. force.

"I would rather be going back to Israel, but we are only moving about a mile and a half down the road," said an Israeli officer stationed here for the last two weeks. The Israelis evacuated another small sector at the eastern end of the occupied zone Tuesday.

Gen. Emmanuel Erskine of Ghana, commander of the U.N. force in Lebanon, escorted the Gurkhas from Nepal to their new positions and told reporters: "Everything is going like machine. No problems." Erskine said the soldiers had not been ordered to prevent Palestinians from returning to southern Lebanon, "but armed personnel are not supposed to come here."

His comments underlined Israeli fears that the U.N. forces will be unable to prevent new hostilities and the guerrilla attacks on Israel of the sort that prompted the invasion March 15.

The Israelis will have pulled out of 16 square miles at the completion of their token withdrawal. U.N. Secretary General Kurt Waldheim has criticized the pullback as too slow, but Israel said in return that the rate of U.N. troop deployment was too slow.

Meanwhile, in Beirut, Saudi and Sudanese troops moved into the tense suburb of Ain Rummaneh to police a cease-fire between Syrian members of the joint Arab peacekeeping force and Lebanese Christian militiamen. The truce, reached Thursday night, generally appeared to be holding.