Turkish President Tayyip Erdogan speaks during the sixth Congress of the ruling AK Party (AKP) in Ankara, Turkey, August 18, 2018. REUTERS/Umit Bektas

ISTANBUL (Reuters) - Turkish President Tayyip Erdogan will visit Iran on Sept 7, his office said on Monday, on a trip expected to include a three-way summit with Russian and Iranian leaders.

The Kremlin said nearly two weeks ago that Russian President Vladimir Putin may take part in a meeting with Erdogan and Iranian President Hassan Rouhani at the beginning of September. The three leaders met in April in Ankara, where they discussed developments in Syria.