U.S. Ambassador Ryan Crocker presented his credentials to Prime Minister Salim Hoss Thursday after reopening the U.S. Embassy, which had been evacuated 15 months ago during fierce fighting.

The decision to send in Crocker despite the still-tenuous security situation reflects U.S. support for President Elias Hrawi's government, which is trying to create a militia-free capital and end 15 1/2 years of civil war.On Wednesday, Crocker was flown by helicopter from Larnaca, Cyprus, to the U.S. Embassy compound in Beirut's northern suburb of Aukar.

The 51-year-old career diplomat became the first American diplomat to enter the compound since it was evacuated by former Ambassador John McCarthy and his staff on Sept. 6, 1989.

Followers of rebel Gen. Michel Aoun had besieged the compound. The Christian general, who battled Syrian troops backing the government, was defeated in October. Militias have since been withdrawing from the capital.

After his one-hour meeting today with Hoss, a Sunni Moslem who doubles as foreign minister to Hrawi's Cabinet, Crocker was whisked to Hrawi's temporary residence in Moslem west Beirut in a bullet-proof gray Mercedes-Benz.

Green-bereted soldiers of the Lebanese army's elite commando brigade provided security for Crocker, surrounding his car with seven jeeps that sped across the jammed streets of west Beirut with lights on and honking horns.