The ministry made the announcement in a statement published on its website on Saturday.
It said observers Jordan, the United States, and the United Nations (UN) were also involved in the preparations.
While the statement did not offer a specific date for the next round of the talks, they are expected in the last week of August, according to previous announcements.
Astana has hosted five rounds of peace talks for Syria since January. Russia, Iran, and Turkey serve as guarantor states in the peace process. The negotiations are aimed at bringing an end to the foreign-backed militancy in Syria, which began in March 2011.
The Astana talks have so far resulted in an agreement on four de-escalation zones across Syria.
The Russian Foreign Ministry statement said three of the enclaves had been created to date, in the country’s sprawling central province of Homs, in the Eastern Ghouta area of the southern Rif Dimashq Province, and a southwestern militant-controlled stretch along the border with Jordan.
Sixth round’s agenda
The upcoming talks, the Russian ministry said, aim to facilitate the creation of the fourth zone, in the western Syrian Idlib Province, where significant concentrations of Takfiri terrorists, most notably from al-Nusra Front, are operating.
The successful materialization of that prospect would “give civilians an opportunity to return to peaceful life” in Idlib.
‘Astana main platform for Syria peace’
The talks in Astana have been going on in tandem with another series of talks, held in Geneva and brokered by the UN.
When the first round of the Astana talks was organized on an initiative by Russia, Iran, and Turkey, the Geneva talks had been stalled for months. The talks in the Kazakh capital then provided momentum for the UN-brokered talks, helping revive them.
But the Geneva talks have achieved little in comparison.
“In the course of events,” the Russian Foreign Ministry said, “Astana has become the main venue for the practical efforts to stabilise the situation in Syria by promoting the steady functioning of de-escalation zones.”
“Importantly, this work is producing concrete results, helping reduce tensions in Syria’s domestic confrontation, increase the living standards of civilians, resolve humanitarian issues, build bridges between various groups of Syrian society and promote trust between them,” it added.
The ministry concluded the statement by hoping for further cooperation on the part of the Syrian opposition.
“We hope the patriotically-minded part of the Syrian opposition will more actively join this uncompromising military, political and ideological struggle.”