In a speech to lawmakers before the vote, Zelenskiy took aim at Honcharuk for failing to halt an industrial slump and for not meeting tax collection targets.

"If in five years, we will end the war, bring our people back, then I did (became president) for a reason," he said.

Ukraine’s President Volodymyr Zelenskiy acknowledged the recording’s authenticity in a report aired by a Ukrainian television channel on Sunday night.

In the leaked recording, Oleksiy Honcharuk called Volodymyr Zelenskiy "a layman'' in economics and said the president should be better educated about the national currency.

Macron told Zelenskiy in a telephone call that France had started a formal procedure to launch an international investigation into the crash, Zelenskiy's office said in a statement, adding that Macron had agreed to visit Kiev.

Russia ships about 40 per cent of its European gas deliveries through pipelines that cross Ukraine.

As the Senate weighs options for a trial, Pompeo will depart Thursday on a five-nation tour of Europe and Central Asia. Ukraine will be the first stop on the trip, the State Department said Monday.

The move was part of an agreement brokered earlier this month at a summit of the leaders of Ukraine, Russia, Germany and France.

Democrats are pushing to call top Trump aides to testify, but Senate Majority Leader Mitch McConnell wants the Senate to consider the case without hearing from new witnesses.

Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskiy met for the first time Monday.