Ukraine and Russia are at odds over Kiev's bid to set up an independent national Orthodox church and break centuries-old ties between the Ukrainian and Russian clergies. Last month, Ukraine's state security service raided the residence of a senior Russian-backed Orthodox priest in Kiev. Ukrainian leaders have accused the Moscow-backed church, widely known as the Moscow Patriarchate, of promoting the Kremlin's interests and spreading propaganda as relations between the countries plummet.

The leader of the Russian Orthodox Church has called on the pope, the UN Secretary-General and other world leaders to help protect Orthodox believers in Ukraine against pressure from local authorities on Moscow-appointed clerics.

The Russian Church issued a statement Friday saying that its leader, Patriarch Kirill of Moscow, had sent a letter to a number of world leaders, urging them to help protect believers in Ukraine and slamming Kiev for interfering in church affairs.

“Lately, the intervention of secular Ukrainian state leaders in church affairs has brought intense pressure on the bishops and clergy of the Ukrainian Orthodox Church,” Patriarch Kirill said, adding that the pressure was the start of “full-scale persecution.”

The Orthodox leader also criticized Ukrainian President Petro Poroshenko for what he called an “unabashed” hostility to the church.

In October, Russian President Vladimir Putin vowed to defend Russian church believers in Ukraine from any “illegal activity” against them.