Secretary of State Mike Pompeo acknowledged on Wednesday that he listened in on the telephone call between Donald Trump and his Ukrainian counterpart that prompted a House of Representatives impeachment inquiry against the Republican US president.

The admission by Pompeo, a key Trump ally, moved the top US diplomat closer to the centre of the scandal and raised further questions about his role in the administration’s interactions with Ukraine, including the recall of the US ambassador to Kiev earlier this year.

The Democratic-led House last week launched its impeachment inquiry, which threatens Trump’s presidency, in the aftermath of a complaint brought by a whistleblower within the US intelligence community over Trump’s request to Ukrainian President Volodymyr Zelenskiy during a July 25 phone call to investigate former Vice President Joe Biden.

Biden is a leading contender for the Democratic nomination to challenge Trump in the 2020 presidential election. Democrats have accused Trump of pressuring a vulnerable US ally to interfere in the 2020 US election to harm a domestic political rival for Trump’s personal political benefit.

“I was on the phone call,” Pompeo told reporters during a visit to Italy.

Pompeo said the call was in the context of US policymaking in Ukraine, including “taking down the Russia threat,” rooting out corruption in government and boosting the economy. The Wall Street Journal first reported that Pompeo was on the call.

Trump has gone all out in his resistance, using language that would once have been inconceivable for a president, including his claim late Tuesday on Twitter that this is “not an impeachment, it is a coup.”

It is “intended to take away the Power of the People, their VOTE, their Freedoms,” Trump said.

Trump made his request to Zelenskiy shortly after he had frozen nearly $400 million in US aid to Ukraine.

Zelenskiy agreed to Trump’s request on the call. The aid money was later provided to Ukraine. Democrats have accused Trump of using taxpayer money as leverage on Ukraine.

Trump, who is seeking a second four-year term as president, has denied wrongdoing and has assailed the impeachment probe.

In an intensifying battle between House Democrats and Trump’s administration, Democratic-led committees have subpoenaed Pompeo and Trump’s personal lawyer Rudy Giuliani, as well as documents.

They will begin depositions of current and former State Department officials this week.

The department’s inspector general, Steve Linick, was due to brief congressional staff on Wednesday to address Ukraine-related documents that have been subpoenaed, according to two sources familiar with the situation.

Pompeo on Tuesday objected to House efforts to obtain depositions and accused Democrats of bullying and intimidation.

Asked about his concerns, Pompeo said State Department employees had been contacted directly by lawmakers or their staff and told not to talk to the State Department’s legal counsel. He said, however, that he would cooperate with Congress. “We will of course do our constitutional duty to cooperate with this co-equal branch but we are going to do so in a way that is consistent with the fundamental values of the American system,” Pompeo said.

The Democratic chairmen of three House committees have accused Pompeo of intimidating witnesses, and said doing so is illegal. They warned Pompeo on Tuesday that he is considered “a fact witness in the House impeachment inquiry” based on his role in Trump’s call with Zelenskiy.

House Oversight Committee Chairman Elijah Cummings intends to subpoena the White House for Ukraine-related records on Friday after what he described as “flagrant disregard of multiple voluntary requests for documents,” according to a memo he sent to the panel.

According to a summary of the July call released by the White House, Trump asked Zelenskiy to investigate Biden and his son Hunter in coordination with US Attorney General William Barr and Giuliani.

Agencies