The United States and Russia have persuaded Syria's government and moderate rebels to extend the country's ceasefire to the northern city of Aleppo, US officials said.
The news came as three people were killed in renewed shelling by Syrian rebels of government-held areas in Aleppo.
The violence in Syria's largest city and once its key commercial centre has continued for almost two weeks despite intense diplomatic efforts to restore the ceasefire.
US officials said they had seen a decrease in violence since the ceasefire extension, agreed on Tuesday night.
But they acknowledged violations were continuing in some areas of the country.
The deal on Aleppo follows reaffirmations earlier this week of truces in the Damascus suburbs and coastal Latakia province.
None of the deals apply to the Islamic State group or the Nusra Front, al Qaida's Syria affiliate, which has caused problems in in places such as Aleppo.
In some battles there and elsewhere, Western and Arab-backed militants have fought alongside those swearing allegiance to al Qaida, making it hard to determine which Syrian government offensives or Russian air strikes constitute violations.
Nearly 300 people have been killed during this latest spate of violence in Aleppo.
Over the past two weeks, hospitals and civilian areas in the divided city have come under attack from government war planes, as well as rebel shelling.