Delegates from the Syrian government and opposition groups attend a fresh round of peace negotiations in Astana, Kazakhstaninfo-icon, in a new phase of the diplomatic process mediated by Iraninfo-icon, Russiainfo-icon and Turkeyinfo-icon.

Thursday's discussions, which are being held behind closed doors, are viewed as a warm-up in the run-up to a separate round of UN-led talks on the Syriainfo-icon crisis slated to be held in the Swiss city of Geneva on February 23.

A one-on-one meeting between Syria's warring sides seems unlikely, but a plenary session involving all parties is on the agenda.

The Syrian government delegation is represented by its Permanent Representative to the United Nationsinfo-icon Bashar al-Ja'afari.

Opposition spokesman Yehya al-Aridi said on Wednesday the opposition will be led by Mohammad Alloush, a leading figure of the Saudi-backed Jaish al-Islam militant group.

The Astana negotiations are expected to focus mostly on bolstering a Syria-wide ceasefire that has been in place since December 30, 2016.

The first round of Astana talks were similarly mediated by Tehraninfo-icon, Moscowinfo-icon and Ankara. They took place in January and brought together representatives from the Damascus government and opposition groups for the first time during nearly six years of conflictinfo-icon.

The trio agreed on the establishment of a mechanism to support the truce, underlined the importance of maintaining the national sovereignty of Syria, and stressed that there was no military solution to the conflict in the Arab country.

Since March 2011, Syria has been gripped by a militancy it blames on some Western states and their regional allies.

De Mistura estimated in August last year that more than 400,000 people had been killed in the crisis until then. The UN stopped its official casualty count in the warinfo-icon-torn country, citing its inability to verify the figures it receives from various sources.