MONTREUX, Switzerland: UN mediator Lakhdar Brahimi meets Syria's warring sides behind closed doors Thursday to gauge if they are willing to sit down face-to-face after the first day of a peace conference ended in bitter exchanges.
Brahimi will hold separate meetings with delegations from President Bashar al-Assad's regime and the opposition before full talks resume in Geneva on Friday.
The UN-sponsored conference -- the biggest diplomatic effort yet to resolve Syria's devastating civil war -- opened in the Swiss town of Montreux on Wednesday with heated disagreements among the two sides and world powers.
But neither side walked out and Brahimi said he would talk with both parties on Thursday to see "how best we can move forward".
"Do we go straight into one room and start discussing or do we talk a little bit more separately?... I don't know yet," Brahimi said.
Officials have said the talks could last between seven to 10 days and possibly resume after a break.
Expectations are very low for a breakthrough at the conference, but diplomats believe that simply bringing the two sides together for the first time is a mark of some progress and could be an important first step.
With no one appearing ready for serious concessions, mediators 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.
Hadi Al-Bahra, a member of the opposition National Coalition's delegation, said they would be meeting with Brahimi in Geneva to work out the details of Friday's talks.
Bahra told AFP the opposition was feeling confident after the regime adopted an aggressive tone for the start of the conference.
"What happened yesterday was clearly in our interest. We have heard very positive feedback from inside Syria and it is the first time we've felt so much support from Syrians for the Coalition," Bahra said.
In a vehement attack during his opening speech, Syrian Foreign Minister Walid Muallem accused the opposition of being "traitors" and agents of foreign governments.
His speech went on three times as long as the allotted 10 minutes and UN leader Ban Ki-moon was forced to repeatedly ask Muallem to wrap it up, drawing the furious response from the minister: "You spoke for 25 minutes."
UN officials were also forced to ask Syrian journalists to calm down during Ban's closing press conference, after they loudly complained of not being allowed to ask questions.
A subsequent press conference by Syria's envoy to the UN, Bashar Jaafari, went on so long that three others, including one planned by the opposition, were cancelled.
"They behaved like the Mafia, with a style very far from diplomacy," Bahra said.
The opposition arrived in Switzerland with a sole aim -- toppling Assad -- while the regime says any talk of removing the Syrian leader is a "red line" it will not cross.
In his opening speech, opposition chief Ahmad Jarba called on the regime to immediately sign an agreement reached at the last peace conference in Geneva in 2012 setting out the transfer of power to a transition government.
US Secretary of State John Kerry backed the opposition's call, saying there was "no way" Assad could stay in power.
Ban urged the two sides to finally work together to save lives.
"The world wants an urgent end to the conflict," Ban said in his closing press conference. "Enough is enough, the time has to come to negotiate."
Top diplomats from 40 nations and international bodies gathered in Montreux and Ban said some could be called back if progress is made in the talks.
Notably absent from the conference was crucial Assad backer Iran, after Ban reversed a last-minute invitation when the opposition said it would boycott if Tehran took part.
In Davos on Thursday, Iranian President Hassan Rouhani said elections would be the best way to end Syria's civil war.
"The best solution is to organise free and fair elections inside Syria," Rouhani told the World Economic Forum. "No outside party or power should decide for the Syrian people and Syria as a country."
Erupting after the regime cracked down on protests inspired by the Arab Spring, Syria's civil war has claimed more than 130,000 lives and forced millions from the homes.
Recent months have seen the conflict settle into a brutal stalemate -- with the death toll rising but neither camp making decisive gains.
Pitting Assad's regime, dominated by the Alawite offshoot of Shiite Islam, against largely Sunni Muslim rebels, the war has unsettled large parts of the Middle East.
Shiite Iran and its Lebanese militia ally Hezbollah have backed Assad; the mainly Sunni Arab Gulf states have supported the opposition; and the violence has often spilled over into neighbouring Lebanon and Iraq.
Much of the fighting in recent weeks has been between opposition forces themselves, as rebel groups combined to attack bases of the Islamic State of Iraq and the Levant, or ISIL, an Al-Qaeda linked group.
Al-Qaeda chief Ayman al-Zawahiri late Wednesday called for the clashes to stop, urging in an audio message posted on the Internet for "every free person in Syria seeking to overthrow Assad... to seek an end to fighting between brothers in jihad and Islam immediately."