"Hagia Sophia will no longer be called a museum. Its status will change. We will call it a mosque," Erdogan said during a live televised program.
Tourists who will come to visit mosques in Istanbul will visit "Hagia Sophia not as a museum, but as a mosque," the Turkish president said.
Slamming criticism of the decision by foreign officials, Erdogan recalled their silence over the attacks on Jerusalem's (Quds) Al Aqsa Mosque.
"Those who remain silent when Masjid Al Aqsa is attacked, trampled, its windows smashed, cannot tell us what to do about the status of Hagia Sofia," he said.
Hagia Sophia, dubbed the "Eighth Wonder of the World" by some historians, is one of the most visited places in the world in terms of art and architecture history.
Built in 537 CE, it was famous for its massive dome. It was an engineering marvel, the world's largest building at the time. Historians consider it the high point of Byzantine architecture.
From 537 until 1453, it served as an Eastern Orthodox cathedral and the seat of the Ecumenical Patriarch of Constantinople, except between 1204 and 1261, when the Fourth Crusaders converted it to a Roman Catholic cathedral under the Latin Empire. It functioned as a Christian church for 916 years.
When the Ottomans took the city, Fatih Sultan Mehmet converted Hagia Sophia into a mosque in 1453. It had that status for 482 years until 1935, when the founder of the Turkish Republic, Mustafa Kemal Ataturk, converted it to a museum.
Following restoration work during the Ottoman era and the adding of minarets by architect Mimar Sinan, Hagia Sophia became one of the most important monuments of world architecture. With Erdogan's edict, it will again be converted to a mosque.
Source: TRT World