Turkish President Recep Tayyip Erdogan will visit Iran on September 7, his office said on Monday. The trip is expected to include a three-way summit with Russian and Iranian leaders, Reuters said. The Kremlin said earlier that Russian President Vladimir Putin may take part in a meeting with Erdogan and Iranian President Hassan Rouhani at the beginning of September. In April, the three leaders met in Ankara, where they discussed the situation in Syria. Moscow, Ankara and Tehran are involved in the Astana process on the Syrian settlement.