A nationwide ceasefire between Syrian government forces and opposition rebels has come into effect.
Russian President Vladimir Putin said earlier that the ceasefire, which excludes extremist groups such as Islamic State and an al Qaida affiliate, will be guaranteed by Moscow and Turkey.
It will be followed by peace talks between Syrian President Bashar Assad's government and the opposition, due to be held in Kazakhstan.
The ceasefire will include all parts of Syria, including the eastern suburbs of the capital Damascus.
Syria's military said it agreed to the nationwide truce, paving the way for reactivating negotiations to end the conflict.
It added that the ceasefire comes after the "successes achieved by the armed forces", an apparent reference to the capture of rebel-held neighbourhoods of Aleppo earlier this month.
Russian defence minister Sergei Shoigu said the truce will include 62,000 opposition fighters across Syria, and that the Russian military has established a hotline with its Turkish counterpart to monitor compliance.
Russia's foreign minister Sergey Lavrov said US President-elect Donald Trump's administration will be welcome to join the Syrian peace process once he takes office.
Moscow is a key ally of Mr Assad, while Turkey is one of the main backers of the opposition.
Several previous attempts to halt the civil war have failed, but the recent warming of ties between Turkey and Russia may prove to be crucial.
The move comes on the heels of the Syrian army retaking control of Aleppo, Syria's largest city, ending the opposition's four-year hold over parts of the city.
Mr Putin said he had ordered the Russian military to scale down its presence in Syria, where it has provided crucial support to Mr Assad's forces.