ASTANA, September 13. /TASS/. Representatives of the countries acting as guarantors of the ceasefire in Syria - Russia, Iran and Turkey - are expected to hold preliminary consultations in Astana on Wednesday in the run-up to the sixth round of talks on Syria, which begins on Thursday, September 14.

The main issue under consideration is the shaping up of a de-escalation zone in the area of Idlib city. In the follow-up to the previous sessions, agreements were reached in May and July on the functioning of areas for de-escalation in the southwest of Syria, in Eastern Guta and in Homs, regarding which the issues of controller forces remain unsettled so far.

Heading the Russian delegation is the Russian President’s special envoy for Syrian settlement Alexander Lavrentyev. Deputy Foreign Minister Hossein Ansari is leading the Iranian delegation and Deputy Foreign Minister Sedat Onal, the Turkish delegation.

The UN Secretary General’s special envoy for Syria, Staffan de Mistura and the Jordanian Foreign Ministry’s special advisor for political issues Nawaf Uasfi Tel will be acting as observers at the consultations.

A change of the chief negotiator has also taken place in the U.S. team. Performing the duties now is the Acting Assistant Secretary of State for the Near East Affairs, David Satterfield.

Bashar Ja’afari, the Syrian ambassador to the UN is heading the Syrian government delegation and the chief of staff of the Syrian Free Army, Ahmed Berri will represent the armed opposition.

A decision on setting up the zones for de-escalation is featured in a memorandum the parties to the Astana talks endorsed on May 4. It says that a ban on any military activities there including flights of warplanes went into effect there as of May 6. The agreement stays in effect over a period of six months and can be prolonged automatically for another six months.

Units of the Russian military policy ensure tranquility in three of the four de-escalation zones.

Security areas with checkpoints ensuring passage for the population and deliveries of humanitarian aid, as well as stations for monitoring the ceasefire are to be installed along the perimeters of de-escalation zones.

The mapping out of the boundaries of the remaining area, Idlib, is proceeding at a much slow pace than one would like to see. Sources say arguments regarding control over the territory and Iran’s possible role in the process sprang up and resolution of the problem may require political will, the way it happened with the southern de-escalation zone.

The sides reached consent on the latter issue after the Russian-U.S. summit in Hamburg on July 7. On August 23, Russia, the U.S. and Jordan launched a joint monitoring center for southwestern Syria in Amman.

The Russian side has said many a time the negotiations in Astana and the pan-Syrian peace settlement talks in Geneva are fully compatible. Staffan de Mistura upholds this opinion, too.

Russian Foreign Minister Sergei Lavrov has said previously the goal of the de-escalation zones is to stop violence rather than to form enclaves of some kind. Syrian government officials and opposition representatives are already holding dialogue through the national committees there.

"This will be an important addition to the efforts undertaken in Geneva to maintain direct dialogue at the table of negotiations in Geneva under the UN umbrella," Lavrov told a news conference in Jeddah on September 10.