Russia and the US have agreed on a Syrian ceasefire scheduled to come into effect at midnight on February 27, a draft of the plan reveals.
The timing follows US-Russian talks at the weekend.
On February 12, Russia and the US had agreed a truce to come into effect within a week, but that deadline passed and skepticism remains over the new plan.
Violence has continued unabated in Syria, with 140 killed in bombings in Homs and Damascus on February 21.
Some 11 million others have been forced from their homes, of whom 4 million have fled abroad – including growing numbers who are making the dangerous journey to Europe.
Reuters quoted Western diplomatic sources as saying the ceasefire would not include ISIS or the al-Qaeda-linked Nusra Front.
US officials said the plan required government forces and the other armed opposition groups to signal their agreement to the truce by February 26.
An official announcement is expected after President Barack Obama speaks with Russian counterpart Vladimir Putin by phone on February 22.
The deal also sets up a communications hotline and calls for a working group to monitor ceasefire violations.
US Secretary of State John Kerry said on February 21 he and Russian counterpart, Sergei Lavrov, had reached a provisional agreement on the terms for the truce. The two powers back opposing sides in the war, with Russia being President Bashar al-Assad’s strongest ally.
On February 20, President Bashar al-Assad had said he would be ready for a ceasefire, if what he termed “terrorists” did not take advantage of the lull in the fighting.
Government forces, backed by Russian air strikes, have been making advances against rebels around the northern city of Aleppo.
Analysts say there will be huge skepticism about the possibility of an effective ceasefire, given the current fighting and failure of the first deadline.
Even if the partial truce holds, Russia is likely to continue its air strikes, which the US coalition says are mainly targeting anti-Assad forces and are hitting civilians.
It is also unclear whether Kurdish forces, which have been making ground in the north, sparking artillery fire from Turkey, will abide by any truce.