Hundreds of thousands of flag-waving demonstrators flooded the Lebanese capital on Tuesday, in a massive show of support for Syria.
The protest, called by the Syrian-backed Shi'ite militant group Hezbollah, brought much of Beirut to a standstill, and dwarfed recent anti-Syrian demonstrations demanding Syria's ouster.
Hezbollah chief Sheikh Hassan Nasrallah used the forum to warn the United States not to interfere in Lebanon, and said no one can force Syria out of his homeland.
As he spoke, the first of Syria's estimated 14,000 troops in Lebanon began pulling back from several areas near Beirut to positions on the Syrian border. Lebanese officials say Syrian forces will clear northern and central Lebanon this month.
The pullback comes after weeks of pressure from the United States, the European Union and several Arab governments following the assassination of former Lebanese Prime Minister Rafik al Hariri.
Lebanon and Syria say talks on a timetable for a full Syrian withdrawal will begin after the ongoing troop movements are completed.