The Greek Orthodox Church of the U.S. said it is petitioning the United Nations over Turkey’s decision to convert the Hagia Sophia museum into a mosque, the Associated Press reported. The decision to convert the Hagia Sophia has drawn widespread international condemnation amid already heightened tensions with Turkey.

The Greek Orthodox Archdiocese of America said it was urging U.N. special rapporteurs in the areas of cultural rights, minority rights and freedom of religion and beliefs to hold Turkey accountable “for its deliberate policies to erase the cultural heritage of Orthodox Christians,” according to the AP. The building is a UNESCO World Heritage site that was previously accessible to all as a museum.

“By unilaterally changing the status, structure and name of these UNESCO sites, with particular significance to Orthodox Christians, Turkey is in violation of its obligations under international law to preserve cultural heritage and to respect the political, cultural and religious freedoms of Orthodox Christians in Turkey and abroad,” Archdiocese of America counsel Christina Hioureas told The Associated Press in an emailed statement.

President Recep Tayip Erdogan issued a presidential decree in July paving the way for the UNESCO World Heritage site to be turned into a mosque. Located in Istanbul, Hagia Sophia was built in 532 in Constantinople, the capital of the Byzantine Empire, as previously reported. It was the seat of the Orthodox patriarch of the capital, and was briefly a Catholic cathedral in the 13th century following the Fourth Crusade.

It wasn’t until 1453 that the Ottoman Empire captured Constantinople and renamed the city Istanbul, and would soon remove all Orthodox symbols inside the church, per previous reporting. After the defeat of the Ottoman Empire in World War I, secular Turkey was later founded by Mustafa Kemal Ataturk, who ordered Hagia Sophia to be turned into a museum, according to the BBC.

The Greek Orthodox archdiocese “hopes that international pressure from the United Nations, its bodies – including UNESCO, and its member states will motivate Turkey to reverse its decision to convert (the world heritage sites) into mosques.”

“The Hagia Sophia was built 15-hundred years ago to be the cathedral and first church of the Ecumenical Patriarchate,” Greek Orthodox Archbishop Elpidophoros of America told the AP. (RELATED: Turkey Reconverts Another Church Into Mosque, Angering Christians And International Leaders)

“Today, with a heavy heart, we behold the historic and indeed essential Greek Orthodox Christian cultural heritage of Turkey being misappropriated, with the conversion of Hagia Sophia into a mosque,” he told the AP. “To do so is to start down a path toward denial of history, a path that denies the future as well.”

Lina Mendoni, Greece’s culture minister, accused Turkey of reviving “fanatical nationalist and religious sentiment” when the action was announced in July. The head of the Eastern Orthodox Church has also criticized the proposal, saying that Christians would be disappointed if Hagia Sophia became a mosque and that the move would “fracture” East and West, Reuters reported. U.S. Secretary of State Mike Pompeo also urged Turkey to maintain Hagia Sophia as a museum in order to ensure the building is accessible to all, Reuters reported in July.

A month after Erdogan ordered the Hagia Sophia to be converted into a mosque, Istanbul’s Church of St. Saviour in Chora, a Byzantine church dating back to the 4th century, was also handed to Turkey’s religious authority to be turned into a mosque. The church served as a mosque during the Ottoman Empire before it was turned into a museum in 1945.

“This is a provocation against all believers,” the Greek ministry said in a statement in response to the announcement, according to the AP. “We urge Turkey to return to the 21st century, and the mutual respect, dialogue and understanding between civilizations.”