Turkish President Recep Tayyip Erdogan said that the Heybeliada Theological School (Halki Seminary) in Istanbul would be reopened if Athens were to add minaret towers to the Fethiye mosque, a 17th-century Ottoman mosque in the centre of Athens.

“Look you want something from us, you want the Halki seminary. And I tell you (Greece), come, let’s open the Fethiye Mosque,” said Mr Erdogan on Saturday during a rally in the northwestern province of Edirne ahead of local elections on March 31.

“They said, ‘we are opening the mosque’ but I said, why isn’t there a minaret? Can a church be a church without a bell tower?

“We say, you want to build a bell tower? Come and do it… But what is an essential part of our mosques? The minarets.”

Mr Erdogan’s speech came after Greek Prime Minister Alexis Tsipras visited Turkey earlier this month.

Mr Tsipras visited Greek Orthodox landmarks such as Hagia Sophia and the now-closed seminary of Halki – the only facility in Turkey where Orthodox clergy can be trained. It’s closure makes it hard for the Greek Orthodox Patriarchate in Istanbul to survive bearing in mind that the Patriarch needs to be a Turkish citizen.

Earlier this month, Mr Tsipras attended a service at the seminary and became the first sitting Greek Prime Minister to visit it since 1933. He said: “I hope my next visit here will be with President Erdogan, and that together we will open the doors of this school.”

The day before, Mr Tsipras and Mr Erdogan had a joint press conference where the Turkish leader linked the opening of the seminary to the rights of Greek Muslims in western Thrace.