GENEVA/BEIRUT: Syria’s government delegation quit U.N.-led peace talks in Geneva Friday and said it would not return next week unless the opposition withdrew a statement demanding President Bashar Assad play no role in any interim postwar government.

“For us [this] round is over, as a government delegation. He as mediator can announce his own opinion,” government chief negotiator Bashar al-Jaafari said after a morning of talks, referring to U.N. mediator Staffan de Mistura.

“As long as the other side sticks to the language of Riyadh 2 ... there will be no progress,” Jaafari said.

He was referring to a position adopted by Syrian opposition delegates at a meeting in Riyadh last week, in which they stuck to their demand that Assad be excluded from any transitional government.

Jaafari went further in a televised interview with Al-Mayadeen TV: “We cannot engage in serious discussion in Geneva while the Riyadh statement is not withdrawn.”

De Mistura put on a brave face on the impasse, saying in a statement that he had asked the delegations to engage in “talks next week” and give their reactions to 12 political principles.

Previously there had been some speculation the opposition could soften its stance ahead of this week’s Geneva negotiations, in response to government advances on the battlefield. The Syrian civil war, now in its seventh year, has killed hundreds of thousands of people and driven 11 million from their homes. So far all previous rounds of peace talks have failed to make progress, faltering over the opposition’s demand Assad leave power and his refusal to go.

Pressed whether the government delegation would return to Geneva next week, Jaafari replied: “Damascus will decide.” Jaafari said the Riyadh statement was a “mine” on the road to Geneva, and the opposition had purposefully undermined the negotiations.

“The language with which the statement was drafted was seen by us, the Syrian government, as well as by too many capitals, as a step back rather than progress forward, because it imposed a kind of precondition,” he said. “The language is provocative, irresponsible.”

The government delegation had initially refused to confirm it would attend the talks and then arrived a day late, reportedly after securing key concessions, including keeping Assad’s fate off the table. De Mistura himself urged the opposition in September to be “realistic enough to realize they didn’t win the war,” and has urged both sides to approach the talks with “no preconditions.” The opposition, which held brief talks later with U.N. officials, rejected Jaafari’s charge that it was seeking to undermine the talks, and said it sought a “political solution.”

“We have come to this round with no preconditions,” opposition spokesman Yahya al-Aridi told reporters.

“Now, not coming back is a precondition in itself. It’s an expression or a reflection of a responsibility toward people who have been suffering for seven years now,” Aridi said.

Nasr Hariri, the opposition delegation chief, said earlier Friday that his side had come to Geneva for serious, direct negotiations with Assad’s government. So far, government and opposition delegations have not negotiated face-to-face in any Syrian peace talks but have been kept in separate rooms.

“We call on the international community to put pressure on the regime to engage with this process,” Hariri said in a statement.

De Mistura said Thursday the talks would run until Dec. 15, but the government delegation might return to Damascus to “refresh and consult” before a resumption, probably Tuesday.

Amid the uncertainty over the Geneva talks, Moscow has proposed holding a “congress” to bring together the government and opposition in Sochi, the Russian Black Sea resort, but has not set a date.

De Mistura has strenuously insisted that the talks he is leading are the only ones that can lead to a political solution to the crisis.

He published a document Friday evening suggesting 12 principles for a future Syria he believed the two sides could agree, including that the country “shall be democratic and nonsectarian.”

He asked the parties to discuss the points and add their thoughts for next week’s talks, which should focus on drafting a new constitution and elections.

On the ground in Syria, the war is raging in some areas.

Rebels shot down a Syrian regime helicopter Friday near the village of Beit Jin, close to the border with Lebanon, killing three officers onboard, according to the Britain-based Syrian Observatory for Human Rights activist group.