Syria peace talks have begun in Geneva amid confusion overwhether opposition groups will attend.
UN envoy Staffan de Mistura opened the talks by meeting the Syrian government's delegation on Friday afternoon.
However, some opposition leaders have said they want an end to air strikes and blockades by government forces as a precursor to talks.
More than 250,000 people have died in almost five years of war in Syria.
About 11 million others have been forced from their homes as forces loyal to President Bashar al-Assad and those opposed to his rule battle each other - as well as jihadist militants from so-called Islamic State (IS).
The so-called proximity talks are expected to last for six months, with delegations sitting in separate rooms and UN officials shuttling between them.