According to diplomats in Geneva, senior officials from major powers and regional players have failed to overcome their differences on a plan for political transition in Syria put forward by United Nations / Arab league envoy Kofi Annan.
The diplomats also say Russia is continuing to impede a consensus.
They say Russia's delegation pressed its own proposed amendments to Mr Annan's text during the meeting.
Russian diplomats indicated Moscow could not agree to a political solution imposed on Syria.
Russia also says it regrets that Iran, Saudi Arabia, Jordan and Lebanon were not invited to the talks.