U.S. secretary of State Michael Pompeo confirmed that he was on the July 25 phone call between President Donald Trump and Ukraine President Volodymyr Zelenskiy that is now at the center of a congressional impeachment inquiry.

“I was on the phone call,” Pompeo told reporters in Rome during a press conference alongside Italian Foreign Minister Luigi Di Maio on Wednesday.

Pompeo, Attorney General William Barr and Trump’s personal lawyer Rudy Giuliani have all been drawn into a House impeachment inquiry after details of the administration’s foreign contacts emerged.

Pompeo said the call was about American policy with respect to Ukraine, including “taking down the threat that Russia poses to Ukraine” and helping get “graft” and “corruption” out of the government there. He didn’t comment on a White House summary of the call that included Trump asking Zelenskiy for help investigating one of the U.S. president’s key political rivals, former Vice President Joe Biden, and his son Hunter, who was on the board of a Ukrainian gas company.

Three Democratic House chairmen warned Pompeo of possible criminal charges Tuesday after he rejected a plan by their committees to take testimony from five State Department officials starting Wednesday. In a letter on Tuesday night, Intelligence Chairman Adam Schiff, Oversight & Reform Chairman Elijah Cummings and Foreign Affairs Eliot Engel said Pompeo “appears to have an obvious conflict of interest” because he listened to the call.

Pompeo said Wednesday he didn’t object to State Department officials testifying but that “there are important constitutional prerogatives that the executive branch has” to protect information, including from allies.

“What we object to was the demands that were put that deeply violate fundamental principles of separation of powers,” Pompeo said. “They contacted state department employees directly. They told them not to contact legal counsel at the state department. At least, that’s been reported to us.”