U.N. Secretary-General Ban Ki-moon says international envoy Kofi Annan's peace plan is the only option right now for ending the violence in Syria.
Ban said in an interview Thursday with CNN's Christiane Amanpour that "at this time, we don't have any plan B."
The former U.N. secretary-general's plan calls for a complete cessation of violence but Ban said "unfortunately, this has not been implemented."
He said the deployment of U.N. observers to Syria has had "some dampening effect" but the violence hasn't stopped. Ban said this requires "strong political will" by Syrian President Bashar Assad and full cooperation by opposition forces.
Ban said he spoke Wednesday to Annan, who said he will be going to Syria soon but no date has been fixed.