BEIRUT/MOSCOW: As President Bashar Assad’s army closed in on the last rebel enclave in Aleppo Tuesday, Russia, Iran and Turkey said they were ready to help broker a Syrian peace deal.

The Syrian army used loudspeakers to broadcast warnings to insurgents that it was poised to enter their rapidly diminishing area during the day and told them to speed up their evacuation of the city.

Complete control of Aleppo would be a major victory for Assad against rebels who have defied him in Syria’s most populous city for four years.

Ministers from Russia, Iran and Turkey adopted a document they called the “Moscow Declaration,” which set out the principles that any peace agreement should follow. At talks in the Russian capital, they also backed an expanded cease-fire in Syria.

“Iran, Russia and Turkey are ready to facilitate the drafting of an agreement, which is already being negotiated, between the Syrian government and the opposition, and to become its guarantors,” the declaration said.

Turkish Foreign Minister Mevlut Cavusoglu said Daesh (ISIS) and Al-Qaeda’s branch in Syria, Jabhat Fatah al-Sham, would be excluded from the deal.

The move underlines the growing strength of Moscow’s links with Tehran and Ankara, despite the murder Monday of Russia’s ambassador to Turkey, and reflects Russian President Vladimir Putin’s desire to cement his influence in the Middle East and beyond.

Putin said last week that he and his Turkish counterpart Recep Tayyip Erdogan were working to organize a new series of Syrian peace negotiations without the involvement of the United States or the United Nations.

For his part, U.N. Syria mediator Staffan de Mistura intends to convene peace talks in Geneva on Feb. 8.

Russian Foreign Minister Sergey Lavrov said after the talks that the three nations believe their efforts could overcome the “stagnation” in the Syrian peace process.

He also said the U.N.-brokered negotiations in Geneva had run into a dead end due to ultimatums from the Syrian opposition in exile.

“The format you see today is the most efficient one,” Lavrov said. “It’s not an attempt to cast a shadow on the efforts taken by our other partners, it’s just stating the facts.”In a telephone call Lavrov and U.S. Secretary of State John Kerry discussed restarting negotiations between the warring sides, the Russian Foreign Ministry said.

In Syria, an operation to evacuate civilians and fighters from rebel-held eastern Aleppo has now brought out 37,500 people since late last week, Turkey said. As more buses left the city Tuesday, Turkish and Russian ministers estimated the evacuation would be complete within two days.

But it is hard to know if that goal is realistic, given the problems that have beset the evacuation so far and the wide variation in estimates of how many have left and how many remain. The International Committee of the Red Cross put the number evacuated since the operation began Thursday at only 25,000.

A rebel official in Turkey told Reuters that even after thousands left Monday, only about half of the civilians who wanted to leave had done so.

Insurgent fighters would only leave once all the civilians who wanted to go had departed, the rebel said. The cease-fire and evacuation agreement allows rebels to carry personal weapons but not heavier arms. Estimates of the number of people waiting to evacuate range from a few thousand to tens of thousands.

The United Nations said Syria had authorized the world body to send 20 more staff to east Aleppo to monitor the evacuation.

A U.N. official said 750 people had been evacuated from the two besieged Shiite villages of Al-Foua and Kfarya, which government forces had insisted must be included in the deal to bring people out of Aleppo.

Conditions for those being evacuated are grim, with evacuees waiting for convoys of buses in freezing winter temperatures. An aid worker said that some evacuees had reported that children had died during the long, cold wait.

In government-held parts of Aleppo, the mood was very different.

A large crowd thronged to a sports hall in the city, waving Syrian flags and dancing to patriotic music, a large portrait of Assad hanging on one wall, in a celebration of the rebels’ defeat in the city that was broadcast live on state television.