UN-Arab League envoy Lakhdar Brahimi is set to meet both Syrian delegations separately on Thursday, a day before their first negotiations when he will try to bring them into the same room.
"Tomorrow I am going to meet them separately and see how best we can move forward," Brahimi, speaking to a news conference after all-day ministerial talks in the Swiss resort of Montreux on Wednesday, said.
The world wants an urgent end to the conflict
"We will try to see if we meet Friday morning separately and hopefully by Friday afternoon both sides will sit in one room," he said later.
Describing the challenge ahead, Brahimi said: "We have no illusion that it is going to be easy but we are going to try very hard."
With no one ready for serious concessions, world powers will be looking for short-term deals to keep the process moving forward, including on localised ceasefires, freer humanitarian access and prisoner exchanges.
Brahimi said he had indications from both sides that they were willing to discuss these issues.
'Enough is enough'
After a day of formal speeches, UN leader Ban Ki-moon urged Syria's regime and opposition to finally work together at the table.
"The world wants an urgent end to the conflict," Ban said in a closing press conference at the talks in the Swiss town of Montreux on Wednesday. "Enough is enough, the time has to come to negotiate."
Ban also told reporters that he had urged the Syrian government to release detainees as a confidence-building measure.
Even if the sides are willing to talk about limited confidence-building measures, expectations for the peace process remain low, with an overall solution to the three-year war still far off.
Russia, which co-sponsored the Montreux meeting with the United States, said the rival Syrian delegations had promised to sit down on Friday for talks which were expected to last about seven days.
About 40 nations and international bodies were gathered, but no direct talks are expected until possibly Friday -- when opposition and regime delegations will meet in Geneva for negotiations that officials have said could last seven to 10 days.