PARIS, Aug 31 (Reuters) - Israeli forces will pull out of southern Lebanon within about 10 days once 5,000 U.N. troops and 16,000 Lebanese soldiers reach the area, United Nations Secretary-General Kofi Annan said on Thursday.

Annan is on a tour of the Middle East trying to calm tensions following the recent fighting in Lebanon and held talks with Israeli Prime Minister Ehud Olmert on Wednesday. "We agreed that with 5,000 U.N. troops and with 16,000 Lebanese troops who will go down to the south (of Lebanon), we will have a big enough and a credible force to allow the Israelis to pull out entirely," Annan told Europe 1 radio.

"I hope that within a week or 10 days we will have the 5,000 troops there and the Israelis will be obliged to withdraw," he said, adding: "It is very important because at the moment the situation is fragile."

Annan said he also expected the Israelis to start lifting their air and sea blockade of Lebanon before the 5,000 troops were fully in place.

Olmert told reporters on Wednesday that Israel would only lift the seven-week-old blockade and fully quit southern Lebanon once all aspects of a ceasefire were in place -- a longer time frame than Annan indicated on Thursday.

U.N. Resolution 1701 which governs the ceasefire halting the war between Israel and Hizbollah guerrillas, calls for a deployment of 15,000 U.N. peacekeepers by Nov. 4, alongside Lebanese army forces.

France has promised to provide 2,000 of the troops. Some 400 are already in place and Defence Minister Michele Alliot-Marie said on Thursday a battalion of some 900 men, with 13 tanks and heavy artillery, would reach Lebanon by Sept. 10.

"The soldiers of the 1st battalion ... will leave on Sept. 4, reach the area on Sept. 10 and from Sept. 15 be fully deployed," Alliot-Marie told reporters.