GENEVA, Dec. 14 (Xinhua) -- The UN Special Envoy for Syria Staffan de Mistura said that the way Intra-Syrian peace talks proceed will come after he speaks to the Security Council in New York as the eighth round ended Thursday without "real negotiations."

He told journalists at the UN in Geneva that the two weeks of talks failed to yield the intended results despite great efforts, which he described as a "missed golden opportunity".

De Mistura said the scheduled topics of a constitution and elections under UN Security Council Resolution 2254 had not even been discussed with the government delegation.

"We did not see the government looking to have a dialogue in this round," said the UN envoy, adding that "there is no alternative but to have the legitimacy of the UN."

He said as well as reporting back to the UN Security Council in New York, he would also seek advice from special ambassadors of the Permanent Five members of the Security Council who he has been consulting.

"I will probably need to come up with new ideas, parameters, about how to move the talks forward, particularly on constitution and elections," de Mistura said.

The UN envoy said that both the government side and the opposition group had accused each other of setting preconditions, but there had been none in Geneva before the talks proceeded.

"We are not going to give up at the moment," he said when "the Syrian people believe there should be some process without precondition."

Earlier, the head of the Syrian government delegation to the Syrian peace talks Bashar al-Ja'afari said his team would not talk to the opposition delegation due to a statement it released before the current talks began, known as "the Riyadh communique."

After a meeting with de Mistura in Geneva, al-Ja'afari told reporters that Syria did not want the talks to fail, but the opposition had come with "a precondition" it set in November at a conference known as "Riyadh 2".

At the conference, a declaration was issued that Syrian President Bashar al-Assad did not have a role to play in the country's future political transition.

"As long as the Riyadh 2 communique stands, we will not engage in direct talks," said al-Ja'afari.

Earlier this week, the Syrian opposition delegation said "there is an opportunity here in Geneva this week that we must take for the sake of our people."

"The opportunity is to sit down, face to face, under the chairmanship of the UN Special Envoy, and begin negotiations on political transition," the opposition delegation said in a statement issued after meeting with de Mistura.

The new round of UN-led Syrian peace talks started on Nov. 28 and was scheduled to be held until Dec. 15. The major obstacle for any expected breakthrough was described by the UN as a lack of trust.

In parallel with the UN-backed Geneva process, a new round of the Russia-led international negotiations on the settlement of the Syrian conflict is scheduled for Dec. 21 and 22 in the Kazakh capital of Astana.