The plan is expected to be carried out in all areas where the Assad regime and the opposition are fighting, the source told Anadolu news agency, who asked not to be named due to restrictions on talking to the media.
The source said that under the plan, Ankara and Moscow will work for the cease-fire to come into effect by midnight on Wednesday.
It added that terrorist organizations will be excluded from the deal.
The source also said that if the cease-fire succeeds, political negotiations will start in the capital of Kazakhstan under Turkey and Russia’s guidance.
Russian President Vladimir Putin said on Friday that Russia and Turkey had agreed to an earlier proposal to bring together representatives of the Syrian regime and opposition in Kazakhstan.
Kazakh President Nursultan Nazarbayev has expressed his “readiness” to provide a platform for talks in Astana to solve the long-standing crisis.
On December 22, the government forces announced full control of eastern Aleppo ruled by insurgents since 2011.