The first meeting meant to discuss the contentious issue of a Syrian transitional government broke up less than an hour after it began Monday following a tense session that one delegate described as "a dialogue of the deaf."
The Syrian government has said it will not discuss replacing President Bashar al-Assad as the leader of a country his family has ruled since 1970.
The opposition insists he must step down in favour of a transitional governing body with full executive powers that would lead the country until elections are held.
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The UN envoy, Lakhdar Brahimi, managed to get both sides to sit in the same room over the weekend to discuss humanitarian aid to besieged areas of the central city of Homs and a possible prisoner exchange. But the opposition said little progress has been achieved.
On Sunday, after three days of talks, a tentative agreement was reached about the evacuation of women and children trapped in Homs before aid convoys go in, although as of Monday night there had been no progress on the ground.
Brahimi cited security problems for part of the delay. The opposition delegation does not control armed groups inside Syria, including al-Qaeda-backed militants, who do not feel bound by agreements reached in Geneva.
On Monday, the two delegations were supposed to begin discussing thorny political issues such as Assad's future.
As the meeting got under way, the government delegation put forward a paper focusing on the need to combat terrorism and halt funding and shipments of weapons to rebels fighting to topple Assad, delegates said.
'Today we will start talking about a new Syria, about transition from starvation to freedom, from torture to human rights and rule of law.' - Syrian opposition spokesman Monzer Akbik
Bouthaina Shaaban, an Assad adviser, called the paper an "expression of good will" in search of common ground and said she was surprised the opposition rejected it.
"Either these people have no capacity to express their love and care for Syria, or they are ordered by foreign powers to ignore what is most important and most urgent for their country," she said.
The opposition called the paper a deviation from the main goal of the talks: a transitional government.
Murhaf Joueijati, a member of the National Syrian Coalition opposition group's negotiating team, criticized the government negotiators. "They began to get even more confrontational and began to lecture in a very dictatorial manner," he said.
"We thought there was no point in continuing this since it was going to be a dialogue of the deaf," he said.
Brahimi broke up the meeting and was scheduled to meet with both sides separately later Monday.
The inability of the two sides to discuss Assad's future was expected.
One of the key guiding principles for the talks in Geneva —which are aimed at stopping three years of bloodshed in Syria that has claimed over 130,000 lives, and forced millions from their homes — calls for the creation of a transitional government that both sides accept.
"Today we will start talking about a new Syria, about transition from starvation to freedom, from torture to human rights and rule of law," an opposition spokesman, Monzer Akbik, said Monday.
But Syria has said any discussion of a transitional government excluding Assad would cross "a red line," insisting the talks should focus instead on combating terrorism.
Militants, including foreign fighters, have flocked to Syria to join the fight to topple Assad. The most powerful rebel groups include two the U.S. has formally designated as foreign terrorist organizations: the Iraqi State of Iraq and the Levant and Jabhat al-Nusra.
In setback to the rebels last year, the U.S. suspended deliveries of nonlethal aid to the Syrian opposition after al-Qaeda-linked militants seized warehouses that had been under the authority of a key U.S.-backed leader.
But on Monday American officials said those deliveries, including communications equipment, are being resumed, for now only to non-armed opposition groups.
Regarding Homs, Akbik said the women and children there should decide whether they want to leave or stay after they have received aid.
He accused authorities of blocking a convoy of 12 trucks trying to get into the embattled city and said, "We will judge the regime by what it does, not by what it says."
Shaaban dismissed the aid effort for Homs as a distraction aimed at bolstering the opposition's credentials.
"This is to make a big fuss about taking two trollies to Homs," she said. "Is this why we came to Geneva? Or we came here to solve the problem in Syria?" she said.
Syrian state TV said a Syrian official and a UN representative were meeting in Homs to discuss how to evacuate women and children from rebel-held areas there. It was unclear when the evacuation would start.
Homs Governor Talal Barrazi said the only obstacle facing the flow of food into rebel held areas are "some cases of snipers fire by terrorist groups."
In a statement released by his office, Barrazi said it is willing to evacuate civilians who want to leave the old quarter of Homs to "any place they want to go to" and they will get food and medical supplies.
"We are waiting for an answer from international organization representatives to specify the number of those who want to leave," Barrazi said.