UN mediator Lakhdar Brahimi has conceded progress has been very slow at the first round of talks between the Syrian government and opposition delegations in Geneva.
Speaking at a news conference at the end of a week of discussions, the veteran diplomat said they had made a very modest beginning, and although gaps between the two sides remained wide they had at least engaged.
The peace talks between the government and the opposition National Coalition ended on Friday with no firm agreement on key issues of halting the violence, getting humanitarian aid to besieged communities, and a future political settlement.
Several rebel elements, such as the al-Qaeda-linked al-Nusra Front, are not represented at the Geneva discussions.
The BBC reports the Syrian government and opposition traded insults after the conference ended.
Foreign Minister Walid Muallem said the opposition were immature, while the opposition's Louay Safi said the regime had no desire to stop the bloodshed.
However, Mr Brahimi said he had seen some "common ground", and scheduled more talks for 10 February.
The opposition has agreed to take part, but Mr Muallem refused to commit.
US presses Russia on Syrian weapons
US Secretary of State John Kerry has asked Russia to press its ally Syria into speeding up the removal of chemical weapons.
The US says only about four percent of chemical weapons declared by the Syrian government have so far been removed.
Mr Kerry raised the issue with Russian Foreign Minister Sergei Lavrov on the sidelines of the Munich Security Conference, officials said.
Syria's chemical weapons are due to be removed and destroyed by 30 June.
Under the terms of the UN-backed plan, Syrian authorities are responsible for packing and safely transporting the chemical weapons to the Mediterranean port of Latakia.
The BBC reports the first consignment of 16 tonnes, from two Syrian sites, left Latakia on 7 January.
A further shipment left on 27 January, according to the Organisation for the Prohibition of Chemical Weapons (OPCW).
"Secretary Kerry pressed Foreign Minister Lavrov to push the regime for more progress on moving the remaining chemical weapons within Syria to the port in Latakia," the US State Department official said.
Washington considered progress so far to be "unacceptable", the official added.
The OPCW, which is overseeing the destruction of Syria's chemical arsenal, has been meeting in The Hague to discuss the operation's progress.
Denmark and Norway are providing cargo ships and military escorts to take them to Italy, where they will be loaded onto a US Maritime Administration cargo ship, MV Cape Ray.
The materials will be destroyed in international waters.