Syrian rivals will tackle all agenda items at peace talks this week, including political transition, the United Nations mediator Staffan de Mistura said Friday, warning not to expect "miracles."
The fifth round of stalled UN-backed negotiations have started in Geneva, with a mandate to discuss governance, drafting a new constitution, elections and combating terrorism in the war-ravaged country.
Syrian President Bashar al-Assad's delegation has sought to keep terrorism as the focus, accusing the main opposition High Negotiations Committee of partnering with extremists.
For the HNC, the issue of governance and especially Assad's removal is the top priority.
"All of them have to talk about all four (issues)", de Mistura told reporters after meeting the government and HNC. "That is (the) deal", he added, following the first full day of the round.
Speaking earlier, the regime's lead negotiator Bashar al-Jaafari said his camp had begun talks on the terrorism issue, given "developments on the ground."
Rebels and allied jihadists this week launched two surprise offensives on government positions in Damascus and central Hama province.
The HNC delegation chief Nasr al-Hariri told reporters the opposition had focused on political transition first.
The sides are meeting separately with the UN.
De Mistura said he would aim to mesh the ideas shared on all subjects by both sides when the round ends next Friday.
"I am not expecting miracles, I am not expecting breakthroughs ... and I am not expecting breakdowns," the UN envoy said, reiterating that agreement on the agenda was itself a mark of progress.
The fact that talks were going ahead despite an escalation of violence was also a "sign of maturity" among the rival camps, he said.
De Mistura added that he will fly to Jordan's capital for one day on Monday to brief an Arab League meeting on the negotiations, with his deputy Ramzy Ezzeldin Ramzy leading the round for a day.
Four previous rounds have yielded little with the government emboldened following major military victories in recent months helped partly by strong support from its ally Russia.
Years of diplomatic efforts have failed to end the Syrian conflict, which has killed more than 320,000 people and displaced millions since it started in March 2011 with protests against Assad's regime.