Representatives of the Syrian government and opposition have wrapped up four days of talks in Moscow, with an opposition leader calling for a third U.N.-sponsored international conference aimed at resolving Syria's four-year civil war.

It was unclear if any substantial progress was made during the Russian-mediated talks.

The government representatives and the Russian mediator were to speak at separate briefings later Friday.

Qadri Jamil, a former deputy prime minister who now represents the opposition Popular Front of Change and Liberation, was quoted by Russian news agencies as saying that further talks in Moscow should be held only after a third international conference in Geneva.

Leaders of the top opposition groups did not take part in the talks in Moscow this week or an earlier round in January.