NUR-SULTAN, August 1. /TASS/. The three guarantors of the Astana process on Syria — Russia, Iran and Turkey — plan to hold a trilateral summit on Syrian regulation, a source close to the negotiations' organizers told TASS on Thursday.

The date of the summit has not been determined yet, a source at the Turkish Foreign Ministry informed TASS on Thursday.

"The date is undetermined yet, we are working on this," the source informed.

Earlier on Thursday, a source in the Kazakhstan’s capital close to the organization of the talks on Syria between Russia, Turkey and Iran informed TASS that the summit is planned for September 11.

On July 4, Turkish Presidential Spokesman Ibrahim Kalin stated that the Syria summit would take place in August.

The establishment of the Syrian Constitutional Committee will be announced at the upcoming Russia-Iran-Turkey summit, the source informed TASS.

"Work on forming the Constitutional Committee is in progress," the source added. "It is planned to announce its creation at the upcoming Astana Process Summit."

According to the source, participants in the meeting on Syria that takes place in the Kazakh capital of Nur-Sultan on August 1-2 have reached understanding on the last candidates for the constitutional committee.

The Syrian Constitutional Committee

On January 30, 2018, participants in the Syrian National Dialogue Congress, held in the Russian Black Sea resort of Sochi, decided to establish a constitutional committee that would work out the country’s new constitution. The committee is supposed to include representatives of the Syrian government and opposition, as well as civil society members. Each of the groups will hold one-third of seats in the committee.