Syria's government and opposition finally met face-to-face on Saturday as difficult UN-sponsored peace talks inched forward in Geneva.

After a false start on Friday, the two sides came together in the same room with mediator Lakhdar Brahimi at the UN's headquarters in Europe, his spokeswoman Corinne Momal-Vanian said.

The meeting, during which Brahimi spoke while the two delegations listened, wrapped up in under half an hour. The two sides then broke up into separate rooms with Brahimi expected to shuttle between them.

"It was not easy for us to sit with the delegation that represents the killers in Damascus, but we did it for the sake of the Syrian people," said Anas Al Abda, a member of the opposition negotiating team.

The two sides were expected to be back in the same room on Saturday afternoon for a session the opposition says will focus on humanitarian issues - especially the situation in the besieged central city of Homs - but the regime says will be more general.

Despite being so short, the meeting still marked progress after a difficult first day for the talks saw President Bashar al-Assad's regime accuse the opposition of obstructing the negotiations and threatening to walk away.

Pulled together by the UN, Russia and the US, the two sides are meeting for the first time in the biggest diplomatic push yet to stem the bloodshed after nearly three years of civil war in Syria.

Brahimi announced late Friday that the two sides had agreed to come together, admitting that the process was proving difficult.

The opposition insists the talks should focus on Assad leaving power and the formation of a transitional government based on an agreement reached during a first peace conference in Geneva in 2012.

Expectations are very low for a breakthrough at the talks, which are expected to last about a week, but diplomats have said simply bringing the two sides together for the first time is an important step.

With no one appearing ready for serious concessions, mediators will be focusing on short-term deals to keep the process moving forward, including on localized ceasefires, freer humanitarian access and prisoner exchanges.

The preliminary stage of the conference in the Swiss town of Montreux on Wednesday was marked by fiery exchanges, with Syrian Foreign Minister Walid Muallem labeling the opposition "traitors" and agents of foreign governments.

AFP