UN-brokered peace talks with the Syrian government and opposition began in Vienna on Thursday. Previous rounds of UN-sponsored peace talks saw little progress. Few expect a breakthrough at the two-days talks aimed at addressing issues related to a new constitution, Reuters said. Their host, UN Special Envoy for Syria Staffan de Mistura, however, said on Wednesday it was “a very critical moment.” Russia, Turkey and Iran convened eight Syria meetings in Astana last year, with the stated aim of agreeing de-escalation zones. The Syrian opposition will also decide in the next two days whether to attend the Syrian National Dialogue Congress scheduled to start January 29 in Sochi, Russia, its chief negotiator Nasr Hariri said.