Syria's army has suspended combat operations in eastern Aleppo, Russia's Foreign Minister Sergei Lavrov says.
The move is to allow for the evacuation of civilians trapped in the battle zone. Mr Lavrov said some 8000 people would be taken out.
Government forces have retaken 75 percent of east Aleppo in recent weeks - areas rebels had controlled for four years.
The US welcomed the "indication that something positive could happen but we're going to have to wait and see".
"Our approach to the situation has been to listen carefully to what the Russians say, but scrutinise their actions," said White House spokesman Josh Earnest.
Mr Lavrov said on the sidelines of a European foreign ministers meeting in Germany: "I can tell you that today, combat operations by the Syrian army have been halted in eastern Aleppo because there is a large operation under way to evacuate civilians."
He also said Russian and US military experts would meet in Geneva on Saturday to discuss ways of bringing an end to the violence in Aleppo.
A US state department spokeswoman said Mr Lavrov had spoken to John Kerry and both had agreed to discuss a ceasefire that allows for the delivery of aid and the departure of civilians, but the "specific nature" of Saturday's technical talks "are still to be worked out".
Earlier, a local council leader in Aleppo warned that "150,000 people are condemned to death" in the city.
Brita Haji Hassan, during a visit to UN officials in Geneva, said 800 people had been killed and up to 3500 injured in the city in the past four weeks.
"We demand a safe passage for civilians to leave and an end to the killing, bombing and bloodbath," he said.
Late on Wednesday, 148 mostly disabled and elderly civilians were evacuated from a former old people's home in the Old City, hours after the area fell to government forces.
They were rescued in a joint operation by the Syrian Arab Red Crescent (SARC) and the International Committee of the Red Cross (ICRC).
Many had injuries or conditions which left them unable to move, and had been trapped in the home for days.
Eleven others had died before they could be reached, either caught in the crossfire or because of a shortage of medicine, officials said.