WASHINGTON: US President Donald Trump on Monday said that he might be willing to testify in the impeachment inquiry over his dealings with Ukraine “even though I did nothing wrong.”

Democrats leading the impeachment process in the US House of Representatives have not formally called Trump as a witness in the inquiry into whether he used foreign policy to try to get Ukraine to investigate domestic political opponent Joe Biden.

Denying any wrongdoing, the Republican president has railed on Twitter and elsewhere against the inquiry and attacked witnesses by name in recent days.

House Speaker Nancy Pelosi, a Democrat, said on Sunday in a CBS interview that Trump has every opportunity to present his case, including coming before the intelligence committee holding hearings.

“Even though I did nothing wrong, and don’t like giving credibility to this No Due Process Hoax, I like the idea & will, in order to get Congress focused again, strongly consider it!” Trump said on Twitter.

The public phase of hearings shifts into higher gear this week when a parade of officials will face questioning by Democratic lawmakers seeking details that could link Trump to a pressure campaign against Ukraine.

Eight more witnesses are due to testify in the second week of the televised hearings. They include Gordon Sondland, the US ambassador to the European Union, whose direct interactions with Trump are likely to be a main focus in the investigation of whether the president made security aid to Ukraine contingent on it agreeing to dig up dirt on former Vice President Joe Biden.

A former top White House adviser told House impeachment investigators Ukrainians were advised Sept. 1 that US military aid was being withheld until their president announced an investigation of a company that had hired former Vice President Joe Biden’s son, Hunter.

Tim Morrison, a former senior director of European and Russian affairs at the National Security Council, said Gordon Sondland, the ambassador to the European Union, told him how he had informed a high-ranking Ukrainian official that release of $400 million in aid was being linked to the investigations, according to a transcript of his closed-door testimony released Saturday.

The House committee also released testimony from Jennifer Williams, an aide to Vice President Mike Pence, who said she found some of discussion on the July 25 call between the two leaders to be “unusual and inappropriate.”

Morrison also said Sondland later claimed such a statement from Ukraine’s prosecutor general wouldn’t do, because President Donald Trump had told him “there was no quid pro quo, but President Zelenskiy had to do it and he should want to do it.” He added: “Sondland believed and at least related to me that the President was giving him instruction.”

Morrison said in closed-door testimony Oct. 1 that he was among officials who listened-in on the July 25 phone call between Trump and Ukraine President Volodomyr Zelenskiy, which has become the subject of the impeachment inquiry. He testified that it raised some concerns, but that he heard nothing illegal discussed — and that a rough transcript of the call later released by the White House was “accurate and complete.”

Contradicts Vindman

That contradicts testimony from at least one other witness, Lieutenant Colonel Alexander Vindman, the National Security Council’s top Ukraine expert, who has testified he also listened in on that call and that the memo summary left out some phrases, edits he tried to put back in — including a mention, by name, of Burisma, the energy company on whose board Biden’s son Hunter Biden served.

Morrison also said NSC lawyer John Eisenberg told him the transcript of that call was not intended to end up in a highly classified system. “It was a mistake,” Morrison said Eisenberg claimed.

Pence’s aide Williams, who also was on the call, kept notes and told investigators the energy company was mentioned. “My notes did reflect that the word Burisma had come up in the call, that the president had mentioned Burisma,” she testified, her recall more in line with Vindman. She also said she felt “the mention of these specific investigations” into the Bidens and the 2016 election was “unusual and inappropriate.”

“I believe I found the specific references to be “- to be more specific to the President in nature, to his personal political agenda, as opposed to a broader foreign policy objective of the United States,” she said.

It is Sondland who has emerged as a central figure in Trump’s alleged efforts to leverage nearly $400 million in US military assistance in return for Ukraine investigations of Biden, a potential Trump 2020 presidential campaign opponent, and other Democrats.