Updated

NEW YORK -- The United Nations Security Council voted unanimously Saturday to authorize an observer mission to monitor the cease-fire in Syria.

The vote came after two days of intense negotiations over the wording of the draft resolution.

Russia, which has veto power on the panel, said Saturday it would back the resolution because Moscow found it "balanced" and it sends a strong message to both the Syrian government and armed opposition forces.

The resolution will allow an advanced party of up to 30 monitors to go to Syria to monitor a cease-fire brokered by former UN Secretary-General Kofi Annan.