UN mediator for Syrian peace talks Lakhdar Brahimi is to hold separate talks with rival delegations to assess their willingness to meet together.
The behind-the-scenes negotiations follow the first day of a major peace conference in Switzerland which ended in bitter divisions.
Mr Brahimi's initiative takes place before full talks resume on Friday.
It remains unclear whether the two sides will negotiate face-to-face - as planned by the UN - when talks restart.
The BBC's diplomatic correspondent Bridget Kendall in Montreux says that while the peace process may have got off to a rocky start - with heated disagreements on Wednesday - at least neither of the two rival delegations from the government and the opposition walked out
The UN special envoy Lakhdar Brahimi (left) is not sure he will get the two sides to talk face to face as planned on Friday
And both say they will come to the UN brokered talks due to begin in Geneva on Friday.
But our correspondent says that how those talks will work is still not certain.
Mr Brahimi has revealed that he still does not know if the two sides are even prepared to sit in the same room.
He intends to consult them separately on Thursday to gauge what is possible.
"What we will try to do is talk about how to end this bloody war, and for that, I think, we have a kind of road map in the communique of 30 June 2012, and we'll see how we use that platform to best effect," Mr Brahimi said.
"We have no illusion that it is going to be easy, but we are going to try very hard."
If all goes well, the hope seems to be that the big political questions which they cannot agree on will be sidestepped, our correspondent says.
Syria's government and opposition were in the same, very large, room, but they didn't negotiate. Instead they made angry speeches.
In between, the world's most senior diplomats, Ban Ki-moon, John Kerry and Sergei Lavrov, tried to remind them that the point of these talks was not to trade accusations about who started the war, but to try to find a way to end it (and bring some relief to Syria's long suffering people).
But at the close of this first day the mood feels bleak. The UN special envoy Lakhdar Brahimi is not sure he will get the two sides to talk face to face as planned on Friday. He wants to talk to them separately first: on the agenda is not immediate peace, but local ceasefires, and better access for aid agencies.
No-one thought these talks would be easy, or quick, but if anyone needed reminding just how much bitterness Syria's three-year conflict has created, day one of the talks provided a graphic illustration.
Instead concrete steps such as local truces and access for aid convoys in Syria will be discussed. But with the lack of trust on either side, even that may collapse into disagreements.
The BBC's Imogen Foulkes, who is at the conference, says that an immediate peace deal is not on the agenda. Neither is a transitional government nor the removal of President Bashar al-Assad.
Instead UN officials are hoping for anything that may bring some small relief to the millions of Syrians who have suffered so much - including the families of more than 100,000 people who have died in the conflict.
Iran, Syria's main ally in the region, has been excluded from the talks in Switzerland, despite earlier being invited by UN Secretary General Ban Ki-moon.
Speaking at the World Economic Forum in Davos, Iranian President Hassan Rouhani called for the Syrian opposition and government to sit round a table as the prelude to "free and fair elections".
It was for the Syrian people to decide their future, he added.
"No outside party or power can decide for the Syrian people and Syria as a country. We all have to help the people."
'Enough is enough'
At a fractious news conference in Switzerland late on Wednesday, during which there were repeated calls for calm, Mr Ban spoke of the suffering in Syria, saying: "Enough is enough. The time has come to negotiate."
US Secretary of State John Kerry said: "There is no way - no way possible in the imagination - that the man who has led the brutal response to his own people could regain the legitimacy to govern."
However, earlier on Wednesday Syrian Information Minister Omran al-Zoubi told reporters: "There will be no transfer of power and President Bashar Assad is staying."
Another key sticking point is the Geneva I communique, agreed at a previous summit, which calls for a transitional government in Syria with full executive powers and which forms the basis of this new round of talks.
Syria has indicated that ending what it calls "terrorism" must be a priority of the communique.
But the head of the main opposition National Coalition, Ahmad Jarba, said the Syrian government must sign up to a deal to transfer powers.http://www.bbc.co.uk/news/world-middle-east-25855027