Russia announced Friday it was negotiating with the Syrian opposition and seeking a nationwide ceasefire, as the evacuation of civilians and fighters from the last rebel-held parts of Aleppo entered a second day.
President Vladimir Putin's intervention came as Russian drones and troops supervised the hard-won evacuation deal following a Western outcry over the Syrian army's operation to recapture the city.
Thousands of traumatised civilians boarded buses and ambulances in freezing temperatures as the operation continued through the night.
"The next step (after Aleppo) will be to reach agreement on a complete ceasefire across all of Syria," Putin said on the sidelines of a visit to Japan.
"We are actively negotiating with members of the armed opposition, with the mediation of Turkey."
Government ally Russia and rebel backer Turkey jointly brokered the deal that has seen thousands of people cram into buses, ambulances and pick-up trucks to flee the last pocket of rebel-held Aleppo since Thursday.
The evacuation deal, which will allow Syria's government to claim full control of the city after years of fighting, was expected to continue throughout Friday.
"It will continue all through today and for so long as there are people who want to leave," said International Committee of the Red Cross spokeswoman Ingy Sedky.
Initially, evacuees were leaving via single convoy of ambulances and green government buses that travelled back and forth between Aleppo and rebel-held territory in the west of the province.
But overnight, the vehicles began returning individually to collect more evacuees as soon as they had dropped off their passengers, Sedky said.
"That means it is difficult for us to know exactly how many people have left so far, but there will be an assessment by the end of the operation," she said.
The Syrian Observatory for Human Rights, a Britain-based monitor of the war, estimated some 8,500 people had left so far, including around 3,000 rebel fighters.
Syrian state media reported a figure of around 8,000.
Ahmad al-Dbis, a doctor helping coordinate the evacuation of the wounded, said at least 500 evacuees had wounds or illnesses requiring medical attention.
He said some people were arriving in private vehicles, including pick-up trucks stacked with household items.
From a gathering point near the town of Khan al-Aasal, people were travelling further west, heading either to camps for the displaced or to stay with relatives or friends.
- Fears for remaining civilians -
The departures began a month to the day after government forces launched a major offensive to retake all of Aleppo, and will hand the regime its biggest victory in more than five years of civil war.
In a video message to Syrians on Thursday, President Bashar al-Assad said the "liberation" of Aleppo was "history in the making".
But US Secretary of State John Kerry said what had already happened in the city was "unconscionable", raising concern for the "tens of thousands of lives that are now concentrated into a very small area of Aleppo".
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"And the last thing anybody wants to see... is that that small area turns into another Srebrenica," he said, referring to a 1995 Bosnia war massacre.
The UN Security Council will meet Friday to discuss a French call for international observers to monitor the evacuation and ensure aid deliveries.
The UN estimated around 250,000 people were living in rebel east Aleppo when the government assault began in mid-November, although officials have since acknowledged that figure might have been incorrect.
As the army advanced, tens of thousands of people crossed to parts of the city held by either the government or Kurdish forces.
UN envoy Staffan de Mistura said on Thursday that perhaps 50,000 people remained in the last rebel-held districts, 40,000 of them civilians.
The evacuation plan had been due to begin on Wednesday but was put on hold after objections from the government delayed the operation and clashes erupted.
- 'We will return' -
On Thursday, thousands gathered to leave, desperate for relief after months of bombardment and siege but tearful at the prospect of potentially permanent exile.
An AFP correspondent in the city's southern Al-Amiriyah district saw people piling on to green buses, filling seats and even sitting on the floor, with some worried they would not get another chance to leave.
Others were hesitant to board, afraid they would end up in the hands of regime forces, or anguished at the thought of departing.
In the dust on the window of one of the buses someone had traced: "One day we will return".
"The scene was heart-breaking," said ICRC head Marianne Gasser.
"People are faced with impossible choices. You see their eyes filled with sadness."
The ICRC said it was unclear how many people were left in the east but the evacuations could continue for several days.
Meanwhile, there was no movement on a reported deal to evacuate sick and wounded residents from two government-held villages under rebel siege in Idlib province.
The Syrian government and its ally Iran had reportedly delayed the Aleppo evacuation to insist on a similar deal for the villages of Fuaa and Kafraya.
On Thursday, state media said 29 buses were heading to the villages to evacuate residents, but the Observatory said on Friday that no one had yet left.
More than 310,000 people have been killed since the Syrian conflict began with anti-government protests in 2011, and over half the population has been displaced, with millions becoming refugees.
Diplomatic efforts -- including several rounds of peace talks in Geneva -- failed to make headway in resolving the conflict, which saw a turning point last year when Russia launched an air war in support of Assad.
With Aleppo out of rebel hands, the largest remaining rebel bastion is Idlib province, which is controlled by an alliance dominated by former Al-Qaeda affiliate Fateh al-Sham Front.