0235 GMT September 25, 2018
The meeting is scheduled to be held in the Russian port city of Sochi.
The Russian foreign minister also held separate talks with his Turkish counterpart Mevlut Cavusoglu over the phone and discussed the upcoming meeting.
On November 22, 2017, the Iranian, Russian and Turkish presidents held talks on the Arab country’s crisis in Sochi.
Following their meeting, the three presidents attended a press conference and issued a joint statement.
During the press conference, Iranian President Hassan Rouhani said the tripartite meeting discussed holding an all-Syrian congress, which will see representatives from all sides in Sochi to exchange views on the fate of the country and pave the way for the drafting of a new Constitution and elections.
Russian President Vladimir Putin also said that the three leaders had agreed to a "congress" of Syria's government and opposition forces in Sochi, adding that they had instructed their diplomats, security and defense bodies to work on the composition and date of the congress.