State Dept official details White House meeting, shuffling of Ukraine portfolio in closed-door deposition George Kent warned of a "smear" campaign against the U.S. ambassador to Ukraine.

A senior State Department official told lawmakers Tuesday that acting White House Chief of Staff Mick Mulvaney organized a White House meeting at which Energy Secretary Rick Perry, US Ambassador to the European Union Gordon Sondland and U.S. envoy to Ukraine Kurt Volker were put in charge of Ukraine policy, according to a lawmaker present for the closed-door deposition.

The move circumvented established policy-making channels in the executive branch and undermined US policy to promote the rule of law in Ukraine, Deputy Assistant Secretary of State George Kent told Congress, according to Rep. Gerry Connolly, D-Virginia.

"Sondland, Volker and Rick Perry declared themselves the three people now responsible for Ukraine policy," Connolly, D-Virginia, told reporters after attending part of the deposition for Kent, whose portfolio includes Ukraine.

"They called themselves 'the three amigos,'" said Connolly, a member of the Oversight Committee. "Volker called them that."

Connolly said the meeting organized by Mulvaney took place on May 23, just days after US Ambassador to Ukraine Marie Yovanovitch -- who testified before lawmakers last week -- was prematurely recalled from her post.

Kent testified that there had been a "parallel process that he felt was undermining 28 years of US policy in promoting rule of law in Ukraine," Connolly said. "And it was wrong. And he used that word: wrong."

The House investigation centers on whether the president and his personal lawyer Rudy Giuliani were conducting a shadow foreign policy to get Ukraine to launch an investigation into former Vice President Joe Biden and his son Hunter's business dealings in the country, as well as into the unfounded theory that Ukrainian officials interfered in the 2016 election to support Hillary Clinton.

Kent was the fourth U.S. official to comply with a request for a deposition by the three House committees that are leading an impeachment inquiry into President Donald Trump, in another crack in the White House stonewall strategy painting the probe as illegitimate and unfair.

Kent, who testified for roughly ten hours, was subpoenaed after the State Department directed him not to appear for his scheduled deposition, according to an official working on the impeachment inquiry

Last week, the State Department likewise said Sondland and Yovanovitch should not testify. Yovanovitch, who served under Republican and Democrat administrations and was named ambassador to Bulgaria by George W. Bush, defied the department's orders and testified for nine hours on Friday.

Sondland is now scheduled to testify on Thursday.

Two former U.S. officials have also testified. One was the former special envoy for Ukraine Kurt Volker. The other was Fiona Hill, Trump's top Russia adviser on the National Security Council, who departed the administration in July, days before Trump's controversial call with Ukraine's new president Volodymyr Zelenskiy.

At the time of the call with Zelenskiy, the administration was withholding a formal meeting between the two presidents and nearly $400 million in security assistance, although Ukraine was not yet aware of the latter.

Like Yovanovitch, Kent is a career foreign service officer. As the Deputy Assistant Secretary, he has overseen policy and communications for U.S. missions in several eastern European countries: Ukraine, Moldova, Belarus, Georgia, Armenia, and Azerbaijan. He's previously served as the deputy chief of mission in Kiev, Ukraine, and the senior anti-corruption coordinator for Europe -- roles that have made him battle-hardened in the fights against corruption and disinformation.

Kent was also a key witness in Trump's firing of Yovanovitch over uncorroborated reports that she badmouthed him and shielded Biden and other Democrats from investigation in Ukraine. In emails that were turned over by the State Department inspector general to Congress, Kent is the one warning senior leadership of efforts to take down Yovanovitch by accusing her of corruption and obstruction -- allegations that have been spread in conservative media.

"Based on what I heard and what I had summarized for me before I got there, he was pretty detailed in talking about some of the shady characters [Rudy] Giuliani was dependent on for misinformation, disinformation," Connolly said.

In one email to acting Assistant Secretary for Europe Philip Reeker and State Department counselor Ulrich Brechbuhl, Kent said there is a "fake news driven smear" against Yovanovitch.

One of the chief allegations against Yovanovitch, made by Giuliani and others, is that she protected Biden and other Democrats by giving Ukraine's prosecutor-general a list of people he could not prosecute. At the time, the State Department called the allegation an "outright fabrication" that "does not correspond to reality."

In the emails, obtained by ABC News, Kent calls it “complete poppycock.”

Kent also noted that the names are not spelled in the standard style of an American diplomat. "This is a classic disinfo play," he adds.

Despite the effort to debunk these allegations, Yovanovitch was recalled from her post in Kyiv in May, just months after she was told she would be asked to stay for an additional year, according to her testimony Friday.

After Kent left the Capitol, Republicans criticized Democrats' handling of the investigation. Rep. Lee Zeldin (R-NY) said if he had subpoena power, "I would love to subpoena Joe Biden."

ABC News' Katherine Faulders contributed to this report.