On Monday Russia and the United States, in a joint statement quoted by Russian news agencies, confirmed their commitment to a cessation of hostilities in Syria and said they would increase efforts to achieve a political resolution to the conflict there.
Moscow and Washington also demanded that all sides in Syria stop attacks on civilians and civilian infrastructure.
In any case, the implementation of the cease fire remains to be verified since Syrian government forces and their allies fought insurgents near Aleppo on Monday and jets conducted raids around a nearby town seized by Islamist rebels, a monitoring group said.
As conflict revived in Aleppo, Syria’s largest city before the war, after a 10-week-old partial truce sponsored by both Washington and Moscow, United Nations peace talks in Geneva also faced a deadlock. The cessation of hostilities and local truces do not include Islamic State or al Qaeda's Syrian branch, the Nusra Front.
The main Syrian opposition has criticized the terms under which the truce is implemented, claiming it allows the Assad regime to reinforce thousands of troops from Iran.