Pence aide testifies in impeachment probe, another transcript released

Jennifer Williams, a top adviser to Vice President Mike Pence, arrived on Capitol Hill Thursday to testify in the House impeachment probe against the president... as a string of other administration officials have refused to do so.

Former national security adviser John Bolton, who was fired by Trump in September, was called to appear on Thursday... but he was a no-show.

Lawmakers want to know what Pence knew about efforts by Trump - and those around him - to pressure Ukrainian officials to investigate former Vice President Joe Biden and his son Hunter.

Williams - a career foreign service officer who was on the July 25th call between Trump and Ukraine - is one of the last witnesses to testify behind closed doors before public hearings start next week.

As Williams was arriving on Capital Hill, President Trump was lashing out on Twitter… after a report by the Washington Post said he wanted Attorney General William Barr to hold a news conference to say that no laws were broken on Trump’s July 25th phone call with the Ukrainian president when he asked for a favor – the subject of the impeachment probe on Capitol Hill.

In a Tweet, Trump wrote: “The degenerate Washington Post MADE UP the story about me asking Bill Barr to hold a news conference. Never happened, and there were no sources!”

According to the Post, Barr did not comply with the request.

White House adviser Kellyanne Conway pushed back:

(SOUNDBITE)(English) WHITE HOUSE ADVISER, KELLYANNE CONWAY, SAYING:

"And I am a little confused by the entire story line, because the Dept of Justice lead by Attorney General Barr already stated publicly that they were not going to pursue charges they didn't see a violation of campaign finance reform."

Democrats in the House are trying to determine if Trump abused his power, questioning whether Trump withheld $391 million in aid to pressure Ukraine into investigating the Bidens and alleged interference by Ukraine in the 2016 election.

Trump denies any wrongdoing.

Democrats have been releasing transcripts of previous closed-door interviews this week... Thursday saw the release of George Kent's.

The Deputy Assistant Secretary of State told investigators that Trump's personal attorney Rudy Giuliani conducted a quote 'campaign full of lies and incorrect information' against former Ukraine envoy Marie Yovanovitch.

Kent is set to testify in an open hearing on Wednesday.