The resolution, approved unanimously by the UN Security Council on Friday, foresees talks between the rebels and the regime, and a rapid truce.
"The unanimous adoption of the UN Security Council resolution offers a chance for the first time to find a serious solution to the crisis in Syria," Nabil al-Arabi, head of the Cairo-based Arab League, said in a statement.
He said the Arab diplomatic body was ready to continue co-ordinating with the UN envoy to Syria, Staffan de Mistura, in "removing any obstacles that impede the implementation of the resolution".
The UN proposal has been met with scepticism by members of Syria's fractured opposition who insist President Bashar al-Assad must go to achieve peace.
The Istanbul-based National Coalition, the main Syrian opposition grouping, has described the plan as unrealistic.
The United States and Arab allies such as Saudi Arabia insist Assad must leave office as part of the process, but his backers Moscow and Tehran insist this is a decision for the Syrian people.