A military source affiliated with the Syrian regime told SANA that the ceasefire in the zone of De-escalation in Idlib has been approved from the morning of August 31, while retaining the right to respond to any penetrate by terrorists.
Russia announced that a ceasefire by regime forces would be implemented on Saturday morning in Idlib province, which is controlled by mercenary gangs supported by Turkey.
The Russian Defense Ministry said the unilateral agreement would start at 06:00 am (03:00 GMT).
Syrian regime forces have been intensifying their military operations and efforts to re-take Idlib since April.
Troops were able to recapture key strategic locations such as Khan Sheikhoun and the international highway linking Aleppo to Damascus, which they lost five years ago.
The United Nations says hundreds of thousands of Syrians have fled since then, and at least 500 civilians have been killed in Idlib, home to nearly three million people.
The announcement comes a day after UN Emergency Relief Coordinator Mark Lokoc called on the Security Council to take serious action to protect civilians in Idlib.
Previous ceasefire attempts have had little success or progress.
The Russian Center for Reconciliation between the parties to the conflict in Syria had previously announced that the regime forces had launched a "unilateral" ceasefire from midnight on 18 May, but it did not last long.
The regime forces announced days after the resumption of military operations, accusing Turkey of continuing to use terrorist gangs in Idlib.
On August 2, coinciding with the 13th round of the Astana series of meetings, regime forces declared a unilateral truce, but the truce was short-lived as regime forces, with Russian support, intensified military operations in the fourth and final De-escalation zone that remained under the control of Turkey's mercenaries.
Since the breakdown of the truce, regime forces have regained control of more than 66 villages, towns and cities, including Khan Sheikhoun and Mork, where the ninth Turkish observation post is now surrounded by regime forces.