A ceasefire brokered by the US and Russia has come into effect across Syria, but the Islamic State group and al Qaida's branch in Syria, the Nusra Front, are excluded.
The ceasefire aims to reduce violence in Syria with the hope of bringing back representatives of the Syrian government and the opposition to the negotiating table in Geneva for talks on a political transition.
If the cessation of hostilities holds, it would be the first time international negotiations have brought any degree of quiet in Syria's five-year civil war.
The Syrian government and the opposition, including nearly 100 rebel groups, have said they will abide by the ceasefire despite serious scepticism about chances for success.
The United Nations special envoy for Syria said peace talks will resume on Monday March 7 if the "cessations of hostilities" holds.
Staffan de Mistura told the Security Council via video conference from Geneva on Friday that he hoped the ceasefire will provide a chance for humanitarian aid to reach those battered by Syria's five-year civil war and allow for a political solution.
Less than an hour before the cessation of hostilities was set to begin, the 15-member Security Council unanimously endorsed the agreement worked out between the US and Russia.