Syrian peace talks set to open in Geneva this week hit a roadblock when regime leader Bashar al-Assad's government refused to confirm it was attending and instead told the United Nations that no delegation would be arriving on Monday.
The eighth round of talks scheduled to begin on Tuesday are seen as an opportunity to achieve progress toward ending the devastating six-year war after the opposition sent a united delegation to Geneva.
UN envoy Staffan de Mistura however told the Security Council that during weekend talks with his deputy, "the government did not yet confirm its participation in Geneva but indicated that we would be hearing from them soon."
"Last night, we received a message that the government would not travel to Geneva today," De Mistura said via videoconference from the Swiss city.
The envoy stressed that Assad had said following a meeting with Russian President Vladimir Putin last week that he was "ready for dialogue."
"Naturally we know and indeed expect that the government will be on its way shortly, particularly in light of President Assad's commitment to President Putin when they met in Sochi," he added.
The rocky start to the talks came as the regime army pounded opposition-held Eastern Ghouta, outside Damascus, killing 14 people, the Britain-based Syrian Observatory for Human Rights said.
The Observatory says the regime's bombardment of Eastern Ghouta has killed more than 100 people in the past two weeks.
After a meeting in Riyadh last week, Syria's disparate opposition groups agreed to send a united delegation to Geneva, a move that was seen as a boost to prospects for a breakthrough.
- Syrian upper hand -
Despite the united opposition front, Assad's delegation would arrive at the talks with the upper hand after government forces regained control of territory in offensives backed by Russia's military might.
Around two-thirds of Syrians now live in regime-held areas that make up 55 percent of the country.
British Ambassador Matthew Rycroft urged the Syrian government to go to Geneva, saying: "It's very important that they demonstrate that they are prepared to talk ...and get on with it, and that means turning up to Geneva."
On a separate track from the Geneva talks, Russia, Turkey and Iran have proposed holding a "congress" to bring together the warring parties in Sochi, but has not yet set a date for that gathering.
Moscow is seeking UN support for that meeting, but De Mistura told the council that it was "premature for me to say anything regarding this initiative."
"The UN must be front and center" in the Syrian peace process, said French Ambassador Francois Delattre.
Any initiative outside of the Geneva process "would be doomed to fail," he warned.
De Mistura said he would be meeting with the ambassadors from Security Council permanent representatives -- Britain, France, China, Russia and the United States -- in Geneva on Tuesday to discuss the upcoming talks.
The Geneva talks are to focus on elections and the drafting of a new constitution, but opposition demands for Assad to step down appear to have been sidelined.
"This crisis -- one of the worst in the history of the UN -- now has the potential, the real potential to move toward a genuine political process," said the envoy.
More than 340,000 people have died in the six-year war, half of the population has been displaced and the country lies in ruin.
The UN envoy said he expected reconstruction to cost $250 billion.
