Secretary of State Mike Pompeo has vowed US support for Ukraine's new independent Orthodox church following its split with Russia in a meeting with its leader, officials said Thursday.

Pompeo on Wednesday held a closed-door meeting with Metropolitan Yepifaniy, who was enthroned in February after the Ukrainian Orthodox Church broke its three-century relationship with Moscow.

Pompeo congratulated Yepifaniy and the two "shared their concerns about abuses against religious freedom in Russia-occupied Crimea and Russia-controlled parts of the Donbass," the State Department said.

Russian-backed separatists have seized territories known locally as the Donbass, and Moscow in 2014 annexed Crimea, where Russia has required religious organizations to register.

Yepifaniy on Twitter said he spoke to Pompeo about the "shameful situation with freedom of religion in occupied Donbass and annexed Crimea"

"I hope Washington will remain indestructible in its support of Ukraine's sovereignty," he wrote.

Metropolitan Yepifaniy is enthroned as head of the independent Ukrainian Orthodox Church in February 2019
Metropolitan Yepifaniy is enthroned as head of the independent Ukrainian Orthodox Church in February 2019 AFP / Genya SAVILOV

Pompeo had also planned to meet this week with Metropolitan Hilarion, who serves as a diplomat for the Russian Orthodox Church.

But a State Department official said that the meeting did not take place, citing a scheduling conflict.

Pompeo, an evangelical Christian who often speaks of his faith and freedom of religion, met the Ukrainian church leader amid a mounting impeachment inquiry against President Donald Trump that centers on Kiev.

George Kent, a State Department official who was questioned by Congress, was among participants in Pompeo's meeting, according to the Ukrainian Orthodox Church.

In a statement that hinted at the scandal in Washington, the church thanked the United States for its longstanding and "bipartisan" support.

Trump is accused of threatening to withhold vital aid from Ukraine unless President Volodymyr Zelensky agreed to dig up dirt on Trump's domestic rival Joe Biden.