The UN's cultural agency UNESCO Friday said it deeply regretted Turkey's decision to turn the Hagia Sophia in Istanbul from a museum into a mosque, lamenting there had been no prior dialogue on the status of the former Byzantine cathedral. UNESCO chief Audrey Azoulay "deeply regrets the decision of the Turkish authorities, taken without prior dialogue, to modify the status of the Hagia Sophia," the UN agency said in a statement, adding that she had expressed her concern to the Turkish ambassador to the body. sjw/pvh