Syrian forces celebrate their victory in eastern Aleppo
Syrian forces celebrate their victory in eastern AleppoReuters

The battle for Aleppo, Syrian’s second largest city, entered what was described as its "final phase" Monday after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances.

President Bashar Al-Assad's forces held more than 90 percent of the onetime opposition stronghold of east Aleppo, a monitor and military official said, and appeared on the verge of retaking the entire city.

A Syrian military official in Aleppo said late Monday, "We're living the final moments before victory."

"The operation in eastern neighborhoods is entering its final phase", he said earlier, as fierce clashes were reported in the few districts still under rebel control.

An AFP correspondent in government-held west Aleppo said celebratory gunfire could be heard late Monday.

State television showed people celebrating, holding up portraits of Assad and Syrian flags.

"Aleppo residents express their joy at the victory against the terrorists", read a caption beneath the footage, referring to the rebels.

The fall of Aleppo would be the worst rebel defeat since Syria's conflict began in 2011, and leave the government in control of the country's five major cities.

The Syrian Observatory for Human Rights monitor reported the army had captured southeast Aleppo's large Sheikh Saeed district.

Syrian official media confirmed Sheikh Saeed had been retaken, with state television showing what it said was live footage from the neighborhood.

The rebels withdrew from six more districts as government troops advanced, the Britain-based Observatory said.

The retreat leaves opposition fighters confined to just a handful of neighborhoods in southeast Aleppo, the largest of them Sukkari and Mashhad.

"The battle of Aleppo has reached its end. It is just a matter of a small period of time... it's a total collapse," said Observatory director Rami Abdel Rahman.

In the Mashhad neighborhood, residents fleeing the army advance crowded the streets earlier Monday, witnesses said.

Displaced civilians -- many hungry after fleeing without food -- sat on pavements or lay on the street with nowhere else to go, they said.

The AFP reporter said the bombardment of rebel areas was among the heaviest in recent days.

Syria's rebels seized control of east Aleppo in 2012, a year into an uprising that began with anti-government protests but spiraled into a complex multi-front conflict, drawing in proxy powers and jihadists such as the Islamic State (ISIS) group.

More than 300,000 people have been killed in Syria's war, and more than half the country displaced.

The government assault on Aleppo has killed at least 415 civilians since mid-November, the Observatory says, while another 130 civilians have been slain in rebel fire on the city's west over the same period.

Diplomatic efforts to end the conflict have repeatedly failed.

Russia last week said talks were under way with U.S. officials on securing a ceasefire and the withdrawal of all rebel forces from Aleppo.

But despite several high-level meetings there was no progress in halting the fighting.

Moscow is a key Assad ally and launched an air war in support of his forces last year, while Washington and other Western nations have backed rebel forces.

French Foreign Minister Jean-Marc Ayrault said Monday the latest round of Russia-US talks at the weekend failed "because there is double-talk" on Russia's part.

"On the one hand they say: let's talk, let's talk and get a ceasefire," Ayrault said. "On the other hand, they continue the war... aimed at saving Assad and capturing Aleppo."

AFP contributed to this report.