By Selen Temizer

SOCHI, Russia

Officials from Turkey, Russia and Iran were holding technical talks Monday in Sochi, Russia, ahead of a 10th round of Syria peace talks in Astana, Kazakhstan, slated for July 31st.

The Astana talks will address the latest situation in de-escalation zones in Syria's Idlib, the return of the refugees, the release of prisoners and the formation of a committee that will rewrite Syria's constitution.

UN officials and Jordan are taking part in Monday's talks as observers while the U.S. again opted not to send a representative.

The main Syrian opposition group is represented by Ahmed Tuma, the former premier of the Syrian interim government, and the regime is represented by Bashar Jaafari, the regime's permanent representative to the UN.

During the 9th Astana meeting held on May 14-15, all parties agreed to maintain the de-escalation zones and the cease-fire regime.

However, Assad's forces and his allies took control of the de-escalation zones in Homs region, Daraa and in Quneitra following a heavy offensive.

Last week, the regime began military build-up in southwestern Idlib in a bid to attack Syria’s northwestern Turkmen Mountain region, which is located within the de-escalation zones.

Idlib is set to be a top issue during the next Astana meeting as the Turkish delegation is expected to underline the importance of maintaining the cease-fire regime in the region.

Separately, Russia for the first time is expected to bring up the issue of the return of refugees and displaced persons during the meeting.

Russian officials have recently visited Turkey, Jordan and Lebanon, which host the majority of Syria's refugees.

UN Special Envoy for Syria Staffan de Mistura is expected to meet with the Turkish, Russian and Iranian officials on the formation of a constitutional committee.

The regime and opposition had each submitted to de Mistura a list of 50 candidates to represent them in the constitutional committee.