Syrian rebels prepare to withdraw from Aleppo as truce begins

• Syrian army's Aleppo advance slows, but victory in sight
• Syrian troops enter Aleppo's Old City, poised for war's biggest victory
• Syrian army captures part of rebel-held east Aleppo
• UN envoy sees continued US work to end Syria war

The agreement was a result of talks between Russia, Assad's main ally, and Turkey, a leading backer of the rebels, a Turkish government official said. The guns fell silent late on Tuesday in Aleppo. A Reuters reporter in the city said no blasts had been heard after days of near constant bombardment.

Smoke and flames rise after air strikes on rebel-controlled besieged area of Aleppo, as seen from a government-held side, in Syria December 11, 2016. REUTERS/Omar Sanadiki

It was the culmination of two weeks of rapid advances by the Syrian army and its allies that drove insurgents back into an ever-smaller pocket of the city under intense air strikes and artillery fire.

By taking full control of Aleppo, Assad has proved the power of his military coalition, aided by Russia's air force and an array of Shi'ite militias backed by Iran.

"Over the last hour we have received information that the military activities in east Aleppo have stopped, it has stopped," said Russia's U.N. envoy Vitaly Churkin late on Tuesday at a heated meeting of the U.N. Security Council. "The Syrian government has established control over east Aleppo."

Rebels groups have been supported by the United States, Turkey and Gulf monarchies, but the insurgent ranks also include jihadist militants who are not backed by Western countries.

However, Assad is far from winning Syria's complex civil war even after reclaiming the major prize of Aleppo. The rebels fight on from strongholds elsewhere in the country, including in the northwest and in areas south of Damascus.