The number one suspect in the failed coup attempt - the Muslim cleric Fethullah Gulen - remains in the United States and has consistently denied involvement.
President Buhari praised the Turkish President for his foresight and maturity in leading his people to the polls to decide on the future of leadership for the country that will further deepen peace and stability.
International observers are expected to give their verdict on Monday, which could embolden or weaken the opposition's case and determine how Turkey's western allies will respond.
