The leader of Syria's main opposition group says the Arab League observer mission should either prove itself or leave.
Dr Burhan Ghalioun of the Syrian National Council also wants western countries to establish a safe area within Syria and enforce a no-fly zone over parts of the country.
Dr Ghalioun told the BBC that he hoped the United Nations might take over or subsume the League's mission.
About 100 Arab League observers have been in Syria since last week to monitor compliance to a peace plan brokered by the Arab League.