The Syrian government and rebel groups have agreed a nationwide ceasefire from midnight (22:00 GMT) on Thursday.
The deal was announced by Russia’s President Vladimir Putin and confirmed by Turkey. The two nations, which back opposing sides, will act as guarantors.
The High Negotiations Committee (HNC), regarded by the UN as Syria’s main opposition body, confirmed the deal, which excludes jihadist groups.
If the truce holds, peace talks will be held in Kazakhstan within a month.
At least 300,000 people are believed to have been killed in fighting that followed the uprising against President Bashar al-Assad in March 2011.