At a news conference in Geneva late Friday, U.S. Secretary of State John Kerry announced the beginnings of a peace plan for Syria, reports NPR's Alice Fordham.
Kerry was joined in the cease-fire announcement by Sergey Lavrov, Russia's foreign minister.
"The United States is going the extra mile here because we believe that Russia, and my colleague, have the capability to press the [Bashar] Assad regime to stop this conflict and come to the table and make peace," Kerry said.
The deal will be implemented at sundown on Monday, Lavrov said.
"We and the United States take obligation to do our best to engage and make the stakeholders comply with the arrangements in our document, and the Syrians have been informed and agree," he said.
But Kerry noted the history of failed plans in the Syrian civil war and warned that the implementation of this new one is far from guaranteed.
The civil war in Syria, which has its roots in 2011's Arab Spring, has pitted the long-standing Assad regime and its supporters in Russia and Iran against an assortment of secular and Islamist groups — prone to frequent infighting — backed by Sunni and Western countries. The often brutal fighting has displaced millions, many of whom have fled to Europe in an unprecedented refugee crisis.