Geneva, Switzerland - The Syrian opposition has described its first meeting here with the UN envoy in the latest round of peace talks as "generally positive", praising him for being more engaged in discussing a political transition.

The comments came a day after Staffan de Mistura, the UN special envoy for Syria, formally launched the fourth round of negotiations at the UN offices amid low expectations.

The talks are part of the latest political initiative to bring an end to a six-year war that has killed nearly 500,000 people, wounded more than a million, and displaced nearly half the population.

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"We heard positive ideas and suggestions from Mr de Mistura," Nasser al-Hariri, the lead opposition negotiator, said at a news conference on Friday.

"I believe he was more enthusiastic than before in discussing a political transition in Syria. So far there are no specific measures."

Hariri said the opposition presented its "understanding" of points in UN Security Council Resolution 2254 that discuss political transition in Syria, including governance, the formation of a new constitution and new UN-supervised elections.

'Just political solution'

The opposition's goal was to forge "a just political solution that ensures for the Syrian people its aspirations and dreams, for which it has paid a very high price", he said.

Friday's discussions with de Mistura only covered "procedural" aspects of the ongoing talks, Hariri said, adding that specific points about the shape and scope of any transition would be clarified in the coming days.

Opposition officials told Al Jazeera that their delegation would respond on Monday to the framework for political transition submitted by de Mistura.

"What will be discussed in the following days is the make-up of a transitional governing body - as in, who the members of this body would be," Mohammad Sabra, the chief negotiator for the opposition delegation, told Al Jazeera.

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He said the opposition's participation in the latest round of Geneva talks was aimed at finding ways to implement "mechanisms" to "force the Syrian government to comply with UN Security Council resolutions surrounding Syria, if it refuses to do so".

"The regime always claims that it is looking for a political solution," Sabra said.

"So far, it has not said that it refuses to implement the resolutions. Resolution 2118 stipulates that in the case of refusal, the Security Council can take measures based on Chapter VII of the UN Charter [...] to force the regime to comply with international law, so that we can achieve political transition."

Shortly after Friday's news conference, the opposition delegation returned to its hotel and held a closed-door meeting with Michael Ratney, the US special envoy for Syria, and several European diplomats.

Government's account

For his part, de Mistura met the representatives of the Syrian government earlier in the day.

In a brief press conference after that meeting, Bashar al-Jaafari, the lead Syrian government negotiator, said de Mistura had presented his delegation with a "document" whose contents would be discussed at their next meeting.

Though the Geneva talks are seen as the most serious effort in months to put an end to the Syrian war, the starkly different political objectives of the rival sides remain unchanged from previous rounds of negotiations, casting doubt on the possibility of achieving progress.

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For the Syrian opposition, a political transition that ensures the removal of President Bashar al-Assad remains the only option for peace - an issue that his Damascus-based government has consistently refused to consider.

"The only solution that we will accept is to establish a transitional governing body, which Bashar al-Assad will have no role in, not in this transitional period, and not in the future of Syria," Salem al-Muslet, spokesperson for the opposition delegation, told Al Jazeera.

The latest talks almost fell apart before they began on Thursday, after the opposition threatened to skip the opening ceremony over disagreements on the format of the session.