Syria's main opposition group has formally backed out of peace negotiations in Geneva, and declined to set a date for resuming talks.

The chief coordinator of the main opposition bloc called for major powers to urgently re-evaluate a truce that -- he said -- is no longer in place. The opposition group complained of having no real negotation power, but would still leave some experts in Geneva to attend meetings. Opposition figures insist that there can be no peace as long as President Bashar al-Assad stays in power.

Syria's government delegation says the government is prepared to discuss the creation of a new unity government but Assad's position as President remains non-negotiable.