Delegations from Syria's government and the Western-backed opposition hoping to overthrow it will face each other "in the same room" on Saturday for the first time ever, a UN mediator said
The mediator, Lakhdar Brahimi, met separately with the two groups for two days, trying to broker peace - or at least a measure of common ground - in a civil war that has left at least 130,000 people dead.
"We are going to meet tomorrow. I hope that it will be a good beginning, and that we will continue until the end of next week," he said.
Brahimi also said that both sides have accepted the principles of a 2012 communique that called for a transitional governing body to be established
The opposition had demanded the government endorse the communique, known as Geneva 1, before direct talks began.
The meeting will start at the United Nations in Geneva at 10:00am local time (09:00 GMT), an opposition delegate told the Reuters news agency.
"It will be a short session in which only Brahimi will speak, to be followed by another session, a longer session in the afternoon," Anas al-Abdah, the opposition delegate, said.
The announcement from Brahimi came after Syria's government vowed to leave Switzerland if "serious talks" did not begin by Saturday. The opposition, which agreed to the peace talks only under intense diplomatic pressure, had been reluctant to sit face-to-face with a government it insists must yield power.
A transition that will remove President Bashar al-Assad from power is what the opposition insists it has come to Geneva to discuss. But the government says it is there only to talk about fighting terrorism - the word it uses for its enemies - and that no one can force Assad to go.
Fighting still raging
The peace conference aims to stem the violence that has forced millions to flee, destabilised the region and turned Syria into a rallying cry for al-Qaeda-inspired armed groups.
We are bombed and nobody cares ... We will remove this criminal regime by force.
Direct negotiations are seen by many diplomats as the best hope for an eventual end to the war. Until now, both sides had spent their time in Switzerland affirming positions hardened after nearly three years of fighting, calling each other terrorists and blaming each other for driving a once-thriving country into ruin.
As the talks wobbled, fighting raged on Friday in parts of Syria, including near Damascus, the capital.
Government forces bombed rebel-held areas in the northern city of Aleppo, according to the British-based Syrian Observatory for Human Rights and local activists.
Protesters in several Syrian towns demonstrated against the talks, saying Assad had shown with years of military strikes against his people that he favours violence over negotiations.
"We are bombed and nobody cares,'' sang one demonstrator in the town of Sabqa. "The Assad regime doesn't understand the language of dialogue. We will remove this criminal regime by force," read one sign.
But the two sides' willingness to meet with Brahimi - even separately - gave some hope that negotiations might bear fruit. Brahimi himself has said both sides may bend on humanitarian corridors, prisoner exchanges and local ceasefires.