Turkish, Iranian and Russian officials will hold talks concerning war-torn Syria in Tehran on August 8-9, Russian Foreign Minister Sergey Lavrov said Sunday.

According to Lavrov, the main topic of the talks would be strengthening the de-escalation zones in Syria.

"With my Turkish counterpart [Foreign Minister Mevlüt Çavuşoğlu], we discussed preparations for the next meeting of the representatives of Russia, Turkey and Iran, which will be held in Tehran on August 8-9," Lavrov said.

The top Russian diplomat added that he and Çavuşoğlu had also discussed the situation over implementing agreements within the framework of the Astana process.

Lavrov reiterated that three de-escalation zones were already operating – in southern Syria, Eastern Ghouta and north of Homs.

"Currently we are working on the largest and probably the most difficult zone in the province of Idlib," Lavrov said.

Meanwhile, spokesman for the Iranian Foreign Ministry Behram Qassemi has also confirmed that the scheduled meeting will be held in the framework of the Astana talks.

Speaking to Iranian News Agency Tasneem, Qassemi said that the sixth round of a high-level trilateral meeting will convene in the last week of August.

During a meeting in the Kazakh capital on May 4, Turkey, Iran and Russia signed a deal to establish de-escalation zones in Syria.

The three guarantor states agreed to establish de-escalation zones in Idlib, parts of Aleppo, Latakia and Homs, Damascus/Eastern Ghouta and parts of Daraa and Quneitra.

Turkey, Russia and Iran are working on a mechanism of de-escalation zones in Syria involving the U.S. and respective zones assigned to each country.

Turkey and Russia have played key roles in establishing a nationwide cease-fire in the war-torn country and later agreed upon the evacuation of Aleppo in late December 2016. After that, along with Iran, the three countries took the initiative to bring together the Syrian regime and opposition forces in Astana in attempts to sustain a cease-fire agreement and to negotiate a political transition in the country.

They will also plan regulations on the release of detainees and prisoners, as well as for the search for missing people.