The International Committee of the Red Cross (ICRC) hopes to resume the evacuation of civilians and wounded from the Syrian enclave of east Aleppo.
Thousands of people are left in Aleppo, some sleeping on the streets in freezing temperatures, after the evacuation of the rebel-held areas ground to a halt on Friday following a disagreement with pro-government forces.
They were demanding the evacuation of two villages besieged by insurgents. Rebels and a government official have said a new deal that was being negotiated on Saturday to complete the evacuation of rebel-held areas of east Aleppo would involve people leaving the two villages and two other besieged towns, Madaya and Zabadani, near the Lebanese border.
"We are getting ready to resume the evacuation of people from eastern Aleppo, hopefully this morning," ICRC spokeswoman Elodie Schindler said in Geneva on Sunday.
However, a resident inside east Aleppo went to the designated departure place at 5am on Sunday. He said that there were still no aid workers from the ICRC, Syrian Arab Red Crescent, nor any ambulances or buses to take people out.
The Syrian Observatory for Human Rights war monitor said the rebel group formerly known as the Nusra Front was preventing evacuation buses from entering the two besieged Shi'ite villages in Idlib province, al-Foua and Kefraya.
The ICRC urged Syria's warring parties on Saturday to agree quickly on a plan and provide "solid" safety guarantees for evacuees, a day after the operation stalled.
Thousands of cold and scared people including women, children, the sick and injured, remain in the enclave, the aid agency said in a statement on Saturday.
Thousands of people were evacuated on Thursday from the last rebel bastion in Aleppo, the first to leave under a ceasefire deal that would end years of fighting for the city and mark a major victory for Syrian President Bashar al-Assad.
But the talks are proving difficult. Negotiations between pro-government and opposition forces as well as their international backers, were believed to still be going on Sunday to finalise how the evacuations would take place and how many people would leave. It was not immediately clear if fighters were also being evacuated.
A senior Syrian rebel official from the powerful Ahrar al Sham group involved in the talks on Saturday said the deal was being held up by Iran and its allied Shi'ite militias which were insisting people be allowed to leave the two villages before allowing the Aleppo evacuation to proceed.
Aleppo had been divided between government and rebel areas in the nearly six-year-long war, but a lightning advance by the Syrian army and its allies began in mid-November following months of intense air strikes, forcing the insurgents out of most of the rebel-held territory within a matter of weeks
The Syrian Observatory for Human Rights said people are sleeping in the streets. The London-based group also said that no lists of possible evacuees had been prepared yet in the other two besieged towns, Madaya and Zabadani.
The chaos surrounding the evacuation reflects the complexity of Syria's civil war, with an array of groups and foreign interests involved on all sides.
The United Nations Security Council is due to vote Sunday on a French-drafted resolution aimed at ensuring that UN officials can monitor evacuations from Aleppo and the protection of civilians who remain.
