U.S. Secretary of State Mike Pompeo has confirmed that he was on the telephone call between President Trump and the Ukrainian president that is the subject of an impeachment inquiry.

"I was on the phone call," Pompeo told reporters in Rome Wednesday during a news conference with his Italian counterpart Luigi Di Maio.

Pompeo did not give information about the contents of the call, saying only that he was well-versed in U.S. policy toward Ukraine.

In the July 25 call with the Ukrainian president, Trump prodded him to investigate Trump's Democratic rival Joe Biden and his son, Hunter Biden.

Pompeo is under increasing scrutiny from House Democrats leading impeachment proceedings against President Trump.

On Tuesday, Pompeo pushed back on House demands for interviews with State Department officials about the administration's dealings with Ukraine that are at the center of the inquiry.