It is the first phase of a planned deployment of some 15,000 troops approved on August 16 by the Lebanese Cabinet.
Lebanese Prime Minister Fuad Siniora said the move would assert government authority in an area where Hizballah has held sway.
"There will not be any areas forbidden to the army, or regions out of its control, military facilities that are not that of the army's," Siniora said. "[There will be no] display of arms other than the army's, so that there will be no weapons outside the authority of the state of Lebanon."
Israeli Defense Forces officials have announced they have begun pulling back from parts of south Lebanon, handing over control to the existing UN peacekeeping force.
The Lebanese reconstruction effort is already under way as thousands of Lebanese families return to southern Lebanon and suburbs of southern Beirut.
French Offer To Lead UN Force
France announced on August 16 that it is willing to lead an expanded UN force in Lebanon, as long as the presence has a clear mandate.
Defense Minister Michele Alliot-Marie said she hoped a large number of Muslim countries would contribute troops.
At the United Nations, Israeli Foreign Minister Tzipi Livni said Israel would have no objection to that scenario in principle, but added a caveat.
"We expect also some European states to contribute to this international force [for southern Lebanon] and it can be also mixed with some Muslim states," Livni said. "But of course it should be states that [are] not, part of Israel's enemies in a way. But it's going to be a mixed force and I don't want to say about one state 'yes' and one state 'no,' right now."
The force, currently 2,000-strong, could be boosted to up to 15,000 troops under the UN cease-fire resolution.
Largely Muslim Malaysia, Turkey, and Indonesia have indicated they would contribute troops, but there have been no firm commitments yet from any country.
Airport To Reopen
Authorities in Lebanon say Beirut International Airport will reopen today for commercial flights for the first time since the Israeli-Hizballah conflict began.
The resumption of commercial flights will effectively end an Israeli air blockade of Lebanon. A plane belonging to Middle East Airlines, Lebanon's flag carrier, is scheduled to land with civilian passengers at around 1 p.m. local time from Jordan's capital, Amman.
An Israeli naval blockade remains in force.
French officials on August 16 encouraged Tel Aviv to end Israel's blockade of the airport and Lebanese ports.
The United Nations has meanwhile drawn up a plan to deal with an oil spill off the Lebanese coast that was caused by the Israeli bombing of a power station near Beirut.
UN spokesman Stephane Dujarric said the plan, drawn up jointly with the International Maritime Organization, will be presented in Athens today.
"Obviously as we move from a humanitarian relief phase to a reconstruction phase, environmental issues will be looked at and looked at carefully, at the request of the government of Lebanon or at the request of the government of Israel," Dujarric said.
The humanitarian fund of the oil cartel OPEC said it would give $200,000 to help clean up the spill, which has polluted 150 kilometers of shoreline.
(Reuters, AFP, AP)