Pope Francis on Sunday joined an international chorus of condemnation of Turkey's decision to convert Istanbul's iconic Hagia Sophia landmark back into a mosque.
I think of Hagia Sophia, and I am very saddened, Pope Francis said towards the end of his midday sermon in Saint Peter's Square.
It was the Vatican's first reaction to Turkey's decision to transform the Byzantine-era monument back into a mosque, a decision that has already drawn criticism from around the world.
The Vatican newspaper Osservatore Romano on Saturday carried reaction from different countries to Friday's decision to turn the monument from a museum back into a mosque, but without any comment.
A magnet for tourists worldwide, the Hagia Sophia was first constructed 1,500 years ago as a cathedral in the Christian Byzantine Empire and it was there they crowned their emperors.
It was converted into a mosque after the Ottoman conquest of Constantinople in 1453, then became a museum in 1935.
Turkey's President Recep Tayyip Erdogan, who critics say is chipping away at the Muslim-majority country's secular pillars, announced on Friday that Muslim prayers would begin on July 24 at the UNESCO World Heritage site.
Several other Christian leaders have already spoken out against Turkey's decision.
Bishop Hilarion, who heads the Russian Orthodox Church's department for external church relations, described it as a blow to global Christianity.
The World Council of Churches, which represents 350 Christian churches, said it had written to Erdogan expressing their grief and dismay.
The head of the Greek Orthodox Church, Archbishop Ieronymos, on Sunday denounced what he described as the instrumentalization of religion to partisan or geopolitical ends.
The outrage and the arrogance doesn't just concern the Orthodox Church and Christianity but all of civilized humanity ... independently of religion, he added.
Erdogan on Saturday dismissed protests from Russia, the United States, France and UNESCO. Those who do not take a step against Islamophobia in their own countries ... attack Turkey's will to use its sovereign rights, he said.