UN envoy Terje Roed-Larsen will hold talks with Syrian President Bashar al-Asad in Damascus on a timetable for the complete pullout of Syrian forces from Lebanon.
A UN spokesman in Beirut said Roed-Larsen would hold talks with Egyptian and Jordanian officials on Saturday before flying to the Syrian capital later in the day.
He will hold similar talks in Lebanon from Monday.
Roed-Larsen is charged by UN Secretary-General Kofi Annan with following up implementation of a Security Council resolution stipulating a total Syrian pullout from Lebanon.
"He will have discussions with senior officials and others in the region related to the full implementation of Resolution 1559 to prepare the secretary-general's report to the Security Council in mid-April," UN spokesman Najib Friji said.
Roed-Larsen will deliver a personal message from Annan to al-Asad and Lebanese President Emile Lahud, he said.
Damascus completed last month the first stage of a two-phase withdrawal plan, pulling back to the Bekaa Valley and withdrawing nearly half the 14,000 troops it kept in Lebanon.
Annan has said he expects Syria to complete the withdrawal before general elections in Lebanon in May. A Syrian-Lebanese military committee will meet next week to finalise details of the pullout.