A new deal between the US and Russia to enforce a ceasefire in Syria has been reached, with the cessation of hostilities set to come into force on 27 February.

The ceasefire, subject to the agreement between the warring parties, would exclude Islamic State, al-Nusra Front and other groups deemed to be terrorist organizations.

Skepticism about whether it can be enforced will be widespread after a previous planned ceasefire failed to take place. Instead, Russia continued its bombing campaign, sieges of starving towns were never lifted and other confidence-building measures ignored.

But the joint statement by Russia and America will not have been issued on Monday – following extensive talks – unless the two countries had relatively clear indications that its terms will be accepted by the key plays including the Syrian government, the opposition forces sponsored by Saudi Arabia, and by Syrian Kurds.