MOSCOW, July 14. /TASS/. Moscow regrets Ankara’s decision to convert Istanbul’s Hagia Sophia from a museum back into a mosque, Russian Foreign Ministry Spokeswoman Maria Zakharova said on Monday.

"We regret the decision of the Turkish Republic’s leadership on turning Hagia Sophia cathedral-museum into a mosque and resuming Muslim religious services there. The ruling on the museum status passed at the initiative of founder of a modern Turkish state Mustafa Kemal Ataturk in 1934 for many decades turned Hagia Sophia into a symbol of peace and inter-religious accord and played an important role in strengthening the atmosphere of religious tolerance and dialogue between nations," the diplomat said.

The Russian Foreign Ministry hopes that Hagia Sophia will be preserved as a UNESCO World Heritage Site. "We expect that any steps against this unique monument will take into account its unique importance for believers of the entire world," Zakharova said.

Earlier, Russian President Vladimir Putin in a phone conversation with his Turkish counterpart Recep Tayyip Erdogan noted that the decision to change the status of Hagia Sophia as a museum in Istanbul sparked a public outcry in Russia.

Turkey’s Council of State said on July 10 it had revoked Hagia Sophia’s status as a museum. Shortly after that, Turkish President Recep Tayyip Erdogan signed a decree allowing it to be used as a mosque again.

Some Local Orthodox Churches, including the Russian Church, voiced regret over the move. For his part, Pope Francis said he was very saddened by Turkey’s decision.

Hagia Sophia, a Byzantine architectural monument, was constructed between 532 and 537 AD by a decree from then Byzantine Emperor Justinian I.

After the fall of Byzantine Empire in 1453, the cathedral was converted into a mosque. In 1935, under the decree of the Turkish government signed by the founder of the modern Turkish state Mustafa Kemal Ataturk, the building was transformed into a museum. White plaster covering Christian mosaics and murals were removed. In 1985, the building was included on the UNESCO World Heritage’s list of monuments.