Syria's civil war foes held their first face-to-face meeting on Saturday at the start of peace talks to end nearly three years of conflict which has killed 130,000 people and destabilised the wider Middle East.
After a day of delay and fierce recrimination, government and opposition delegates faced each other across a negotiating table at the United Nations headquarters in Geneva in the presence of international mediator Lakhdar Brahimi.
The two parties entered and left the room through separate doors, sitting in silence for half an hour while Brahimi set out his plans - an immediate focus on humanitarian aid which diplomats have described as a confidence-building measure, followed by political talks to resolve the conflict.
"He told us this is a political conference ... based on Geneva 1," opposition delegate Anas al-Abdah said, referring to a June 2012 declaration calling for the establishment in Syria of a transitional governing body by mutual agreement.
President Bashar al-Assad's government delegation said it broadly accepted Geneva 1, but reiterated its longstanding opposition to idea of a transitional body, saying it was inappropriate and unnecessary.
"We have complete reservations regarding it," Information Minister Omran Zoabi said, comparing the proposal to the transitional government set up in Iraq by U.S. occupation forces after they toppled Saddam Hussein in 2003.
"Syria is a state with institutions," he added. "A transitional governing body ... happens where the state is in disintegration, or has no institutions."
The opposition has insisted that the government delegation accept the principle of setting up the transitional body, saying it must bring an end to Assad's rule. The president says only Syrian voters can choose their ruler and that he may well stand again in an election due to be held by June this year.
Delegates reconvened at around 4 p.m. (1500 GMT), a U.N. spokeswoman said, and were expected to discuss a possible deal on a short ceasefire to allow humanitarian aid into besieged rebel-held areas in Homs.
"We will focus over the next two days on humanitarian conditions and letting in food to the besieged areas," opposition delegation spokesman Louay Safi told reporters.
"We will also discuss the release of the prisoners of conscience. There are huge numbers of them. We will start first with women and children".
The peace conference almost collapsed on Friday, the day face-to-face talks were meant to start. "We do expect some bumps on the road," Brahimi said after separate meetings with the parties.
One diplomatic source said progress had been slow.
"Small steps, but small steps are better than no steps," the source said. "It's clear there will be hysterical episodes each day."
Humanitarian access for Homs, where insurgents in central districts are surrounded by Assad's forces, could be agreed quickly. Abdah said the opposition had already asked fighters on the ground to respect a ceasefire and to protect convoys of aid once the agreement is reached.
"We had a suggestion prepared for this before the conference began and already spoke about it to the Red Cross and countries that are close to the regime like Russia, as well as United States and the United Nations," he said.
The proposal, which includes granting civilians safe passage, could lead to a ceasefire in Homs city for a week or two, which if successful could be extended to the whole of the central province - a major battleground.
But profound mutual mistrust and the absence from Geneva of powerful Islamist opposition groups as well as Assad's ally Iran make any substantial progress very difficult, and previous ceasefires in Syria have proved short-lived.
The crisis flared with street protests against Assad's rule in March 2011 and descended into an armed insurgency and civil war after security forces put down demonstrations with force.
There are now hundreds of rebel brigades across the country, including hardline Islamists and al Qaeda-linked militants, few of whom pay much heed to the opposition in exile.
Abdah said the fact that Brahimi had raised the issue on Saturday, after separate talks with the opposition and government delegations a day earlier, meant the ceasefire idea had already won a degree of consensus between the two parties.
Brahimi had already indicated that his aim was to start by seeking practical steps, such as local ceasefires, prisoner releases and access for international aid deliveries, before embarking on the tougher political negotiations.
"I think an immediate political solution is unrealistic, unfortunately," French Foreign Minister Laurent Fabius told France 24 television.
Syria's civil war has made half of the 22 million population dependent on aid, including hundreds of thousands cut off by fighting.