Talks to end Syria's brutal five-year conflict resumed in Geneva today, but were clouded by a surge of violence threatening a fragile truce on the ground.
Adding to the tensions, Syrians began voting in government-controlled areas in a parliamentary election which is not recognised by the United Nations or by President Bashar al-Assad's main opponents.
The UN-brokered talks in Geneva are aimed at forming a transitional government and a new constitution followed by general elections to end a conflict that has killed more than 270,000 people and displaced half of the country's population.
But Assad's fate remains a major stumbling block.
UN Syria envoy Staffan de Mistura met with Assad's key allies Tehran and Moscow ahead of a meeting with the main opposition High Negotiations Committee (HNC) today afternoon and regime representatives later in the week, probably Friday.
Russian Foreign Minister Sergei Lavrov stressed the importance of this round of talks, which is scheduled to last about 10 days.
"The Syrian parties should discuss the new constitution, and how they see the structure that will ensure a peaceful transition towards a new system," he told reporters in Moscow.
A Western diplomat also said "there is more riding on this round" than previous rounds, since de Mistura is looking to tackle the thorny issue of "what does transition away from Assad actually look like".
Before the meeting with de Mistura, HNC advisor Yahya al-Aridi told AFP the opposition would "insist that there's one topic on its agenda: the political transition."
The main question will be whether the regime delegation will agree to broach the issue of Assad's future, which it until now has insisted is off limits.
De Mistura is "walking in a bit of a minefield," al-Aridi acknowledged.
Complicating matters further, a surge in violence in recent days has threatened a landmark ceasefire agreed in February.
This has piled more pressure on the talks, which follow fruitless attempts in previous years to negotiate an end to the bloodshed.
"Right now, there are signs that this (the ceasefire) is slipping and it is a much more delicate environment for de Mistura to convene political talks," US Ambassador to the UN Samantha Power told reporters in New York after a briefing by the envoy yesterday.
Power said Moscow had to put pressure on Damascus to "get the regime back with the programme", adding she was "very alarmed" by Syria's plans to launch a Russian-backed counter-offensive in Aleppo, the epicentre of the renewed fighting.
