Foreign Secretary Philip Hammond has urged Syria's moderate opposition groups to join this week's UN peace talks in Geneva. The appeal comes as negotiators from the High Negotiations Committee (HNC), a body representing the main Syrian opposition groups and factions, met in the Saudi Arabian capital Riyadh to decide if they should take part in the negotiations.
Some opposition leaders are reportedly reluctant to go to Switzerland and have demanded a halt to bombardments by regime forces and the lifting of blockades of besieged areas. The HNC has also insisted that it should be the sole opposition body taking part in the negotiations.
Hammond warned opposition groups that boycotting the 29 January talks would hand Syrian President Bashar al-Assad a propaganda coup.
The five-year Syrian Civil War has claimed the lives of more than 250,000 people. An estimated 4.5 million people have fled the country and some 6.5 million have been internally displaced.
'Lot of posturing'
"For the opposition not to attend the talks would hand a propaganda coup to the regime," Hammond told the Guardian newspaper. "The opposition must engage in talks. We need to focus on confidence-building measures, including a ceasefire."
UN officials say the talks will prioritise a country-wide ceasefire, delivering humanitarian aid and halting the threat posed by the Islamic State (Isis) militant group.
The negotiations will start with proximity talks, with UN diplomats travelling back and forth between the rival delegations in separate rooms, and are expected to last for six months.
"There will be a lot of posturing, we know that, a lot of walk-outs and walk-ins because a bomb has fallen or because someone has done an attack, and you will see that happening," Staffan de Mistura, the UN special envoy for Syria, said at a press conference. "We should not be impressed, neither depressed, but it's likely to happen. The important thing is that we keep the momentum."
De Mistura sent out invitations to the talks on 26 January, but did not reveal which groups and factions had been invited. Several opposition leaders who are not part of the HNC told the AFP news agency that they had received invitations. Syria's Kurdish Democratic Union party (PYD) said it had not been invited amid opposition from Turkey, which considers the party a terrorist group.
"The failure in Syria is most definitely not the humanitarian organisations' failure, it is a political failure," said John Ging, operations director for the Office for the Coordination of Humanitarian Affairs. "That is why we are now looking, with great hope, for this political process to do what is needed, which is to deliver us a solution which will end the conflict and put people back on the track and the path which they deserve."
Yaacoub El Hillo, the UN humanitarian coordinator in Syria, added: "We come with a clear message to those coming to Geneva that enough is enough. "Syrians can no longer continue to pay the price for political failure, and what we see in Syria is indeed political failure at all levels."
The Geneva talks were scheduled to start on 25 January, but have been delayed by a dispute over who should represent the opposition at the negotiating table. The Assad government has appointed its UN envoy, Bashar al-Jaafari, as the chief negotiator of its delegation.