The Syrian military has announced a unilateral 72-hour "regime of calm" cease-fire that should last until midnight on July 8, local and international agencies report.
The statement coincides with festivals in many predominantly Muslim countries marking the Eid al-Fitr holiday that concludes the holy month of Ramadan.
It did not specify a location for the suspension of combat activities.
U.S. Secretary of State John Kerry said during a visit to Georgia that "We very much welcome the Syrian army's declaration of a period of quiet in celebration of Eid. We very much hope it will be honored by all parties."
He suggested the move by Damascus could "be a harbinger of possibilities to come."
A cease-fire brokered by the United States and Russia in February held for a short time before it fell apart amid localized fighting and a failure of international powers to help bring an end to 4 1/2 years of violence that has killed more than 250,000 and forced 11 million Syrians from their homes.
Subsequent breaks in the fighting have quickly given way to fresh violence.
Turkey and the United States are backing elements intent on ousting longtime Syrian President Bashar al-Assad, while Assad-ally Russia has conducted its own bombardment campaign in support of Assad.
Meanwhile, the Islamist militant group Islamic State (IS) controls swaths of Syria and neighboring Iraq that it has declared as a "caliphate" and massacred civilians and captured forces in an effort to control and hold.