Syria's army said Wednesday it will abide by a two-day ceasefire in second city Aleppo agreed between the United States and Russia.

"A truce will be in place in Aleppo for 48 hours from 1:00 am on Thursday (2200 GMT on Wednesday)," a statement from Damascus's army command said, according to the official SANA news agency and state television.

Washington and Moscow agreed earlier Wednesday to work with Syria's warring parties to extend a shaky truce to Aleppo, which has seen more than 280 civilians killed in fighting since April 22.

"To ensure this continues in a sustainable way, we are coordinating closely with Russia to finalise enhanced monitoring efforts of this renewed cessation," US State Department spokesman Mark Toner said.

Last week, Washington and Moscow agreed to monitor a truce between Bashar al-Assad's loyalist forces and opposition in rebels in Latakia and Eastern Ghouta.

But the divided city of Aleppo, a major commercial centre in the north of the country, was excluded from their efforts and fierce fighting continued there.

Russian officials at first said that they would not try to rein in Assad's forces, whom they said were targeting "terrorists" not party to the ceasefire.

But US Secretary of State John Kerry and UN peace envoy Staffan de Mistura have since petitioned Russia for a return to a nationwide truce agreed in February.

"We look to Russia as a co-chair of the International Syria Support Group to press for the Assad regime's compliance with this effort," Toner said.

Once a nationwide "cessation of hostilities" is again in place, the United States and United Nations hope the warring parties will return to peace talks. afp