Setting the agenda proved a delicate task in this round of talks, dubbed Geneva 4, which aimed to restore hope for a negotiated solution to a conflict that has raged for six years and claimed, by most counts, almost half a millions lives.
After nine days, negotiators at the Syrian peace talks in Geneva were unable to agree to meet face-to-face.
Syrian government negotiator Bashar al-Ja'afari accused the Saudi-backed opposition on Thursday of holding peace talks hostage due to their reported refusal to unify under one opposition delegation and include terrorism on agenda. "I know what I heard and what I saw and that gives me some feeling that we are moving in the right direction", he said.
The Syrian government's delegation left without comment.
De Mistura said the United Nations recognised only two terrorist groups: Islamic State and the former Nusra front, once an al Qaeda affiliate.
"While it remains our goal to secure an agreement to move to direct negotiations between the government and the opposition, there is a moment in fact when it is more effective to have a proxy meeting like we have had this time".
Body of missing boy found in Murray River, mother in custody
The 27-year-old mother with a troubled history seems more known about than really known in the town of 8000 people. The father of the boys has spoken of his devastation and said he was numb after learning about what had happened.
"It was first time we discussed in an acceptable depth the issues of the future of Syria and political transition", he added after the talks, the fourth mediated by de Mistura.
Russian representatives met both sides behind the scenes, according to Reuters news agency. He said instead that those who want to be part of the process must come under one umbrella.
Damascus sought a unified Syrian opposition.
A Western diplomat said Russia's push to unify the opposition was an underhand tactic. This is a tactic to weaken the process. De Mistura estimated in August a year ago that more than 400,000 people had been killed in the crisis until then.
03 de marzo de 2017, 17:43Moscow, Mar 3 (Prensa Latina) Russia expects success in the negotiations about Syria in Geneva, to which we never challenged our efforts for a dialogue between the Syrian conflicting sides in Astana, Russian Foreign Vice Minister Serguei Riabkov stated today.
The Astana meetings would deal with "maintenance of the ceasefire, immediate confidence-building measures and operational counter-terrorism issues", the United Nations mediator told a reporters.