The US and Russia have entered an agreement over the cessation of hostilities plan in Syria, which is to be enforced from 27 February.
The two nations are co-chairs of the International Syria Support Group (ISSG) that aims at peaceful settlement of the Syrian crisis with support from the UN.
US State Secretary John Kerry said: "I am gratified to see the final arrangements concluded today for a cessation of hostilities in Syria and call on all parties to accept and fully comply with its terms.
"If implemented and adhered to, this cessation will not only lead to a decline in violence, but also continue to expand the delivery of urgently needed humanitarian supplies to besieged areas and support a political transition to a government that is responsive to the desires of the Syrian people.
The countries have agreed to jointly develop mechanisms to monitor the Syrian Government's and other force's compliance with the ceasefire.
The truce agreement will see the countries establishing a communication hotline and a working group if required to exchange relevant information.
Kerry added: "All parties must meet their commitments under this agreement, ensure full implementation of UN Security Council Resolution 2254, and cease attacks on each other, including aerial bombardments. And all parties must remain committed over a period of time to make possible a political end to this conflict."
Last week, ISIS attacks in the Syrian cities of Damascus and Homs killed nearly 130 people.