Syrian peace talks between the Syrian government and opposition groups that were brokered by Russia, Iran and Turkey are due to start in Astana, Kazakhstan.

The opposed parties aim at finding common ground to stop the six-year-long bloody conflict in Syria.

The talks are scheduled to start at 13:00 local time Monday, according to the head of the Russian delegation in Astana and Russian President’s special envoy to Syria, Aleksandr Lavrentiev.

“Various aspects of the … meeting are still discussed but it will start at 13:00 local time,” Lavrentiev said on Sunday, noting that the talks will be attended by delegations of the host nations – Russia, Iran and Turkey – as well as UN special envoy and the US ambassador to Kazakhstan.

Iranian Deputy Foreign Minister Hossein Jaberi Ansari said on Sunday that Russia, Iran and Turkey are still debating whether there should be direct contact between the opposition delegations and the Syrian government.

Elsewhere in his remarks, Ansari expressed optimism about the potential outcome of the negotiations.

Russia, Iran and Turkey also held trilateral meetings on Sunday that lasted more than five hours and were described as “tough” by a member of the Russia delegation.

“The preparations [to the talks] are going on intensively,” he said, adding that the three countries “managed to bring closer their positions on most issues on the agenda.”