Lieutenant Colonel Alexander Vindman, a US National Security Council official, said Donald Trump made “inappropriate” demands in his July 25 phone call with Ukrainian president Volodymyr Zelensky that sparked the impeachment inquiry.
Col Vindman and Jennifer Williams, an aide to vice-president Mike Pence who also appeared on Tuesday, were the first officials with first-hand knowledge of the call to testify in public, and both said they were troubled when US president pressed his Ukrainian counterpart to investigate former vice-president Joe Biden and his son.
“What I heard was inappropriate,” Col Vindman told the House intelligence committee. which is leading the public phase of the inquiry. “It is improper of the president of the United States to ask a foreign government to investigate a political opponent.”
Mr Trump called the inquiry a “kangaroo court” as the officials testified, while some Republicans on the panel questioned the competence and patriotism of Col Vindman, a decorated army officer who emigrated with his parents from the Soviet Union.
In an effort to rebut the Republican attacks, Col Vindman described how his father had left the Soviet Union to give his family a better life.
“Dad, I’m sitting here today in the US Capitol — talking to our elected professionals [which] is proof that you made the right decision 40 years ago to leave the Soviet Union to come here to the United States of America in search of a better life for our family,” he said. “Do not worry. I will be fine for telling the truth.”
Mr Trump faces the biggest crisis of his presidency after a CIA whistleblower revealed US officials were concerned he had used his office to push for a probe into a political rival, which would amount to foreign interference in a US election.
In the July 25 call, Mr Trump asked his Ukrainian counterpart to find dirt on Mr Biden, one of the contenders for the 2020 Democratic presidential nomination, and the business activities of his son Hunter, a director of Burisma, a Ukrainian gas company.
Mr Trump also enlisted Rudy Giuliani, the former New York mayor who serves as his personal lawyer, to push Mr Zelensky to investigate the Bidens and to look into widely debunked claims that Ukraine had interfered in the 2016 US election.
“Frankly, I couldn’t believe what I was hearing,” Col Vindman told the committee when asked about the call.
Mr Trump has described the July 25 call as “perfect”. He said he was trying to root out corruption in Ukraine and was concerned Hunter Biden had received hundreds of thousands of dollars from Burisma despite having no relevant experience.
Republicans have accused Joe Biden of forcing Ukraine to end a probe into Burisma — a claim debunked by former US aides and officials from other countries and multilateral institutions involved in efforts to stamp out corruption in Ukraine.
Asked by the Democrats on Tuesday if they were aware of any credible allegations about Mr Biden and Ukraine, Col Vindman and Ms Williams both said they were not.
Col Vindman told lawmakers that he believed Mr Giuliani was a “disruptive” actor “promoting false narratives” that undermined Ukraine policy.
Several witnesses have testified that Mr Giuliani ran a parallel foreign policy towards Ukraine. Mr Trump also asked Gordon Sondland, his ambassador to the EU, to help Mr Giuliani, along with Kurt Volker, then special envoy to Ukraine, and Rick Perry, energy secretary. The men dubbed themselves the “Three Amigos”.
Mr Sondland will testify publicly on Wednesday. His testimony is critical because of his first-hand knowledge of the role Mr Trump played, including in the decision to withhold $391m in aid to Ukraine to help defend itself from Russian aggression.
Congressional investigators are trying to determine whether Mr Trump withheld the military aid to pressure Mr Zelensky into probing the Bidens. Mr Sondland testified in private that there was no “quid pro quo” but changed his testimony after other officials testified that Mr Sondland had told them that there was such a link.
Col Vindman also described how Mr Sondland brought two Ukrainian officials to a July 10 meeting with John Bolton, which the then-national security adviser cut short after Mr Sondland told the Ukrainians that Kyiv should open certain investigations.
In a debriefing after the meeting, Mr Sondland reiterated the need for Kyiv to probe the Bidens, which prompted a sharp response from Col Vindman, and raised concerns for Fiona Hill, then senior National Security Council official for Russia policy.
“I stated to Ambassador Sondland that this was inappropriate and had nothing to do with national security,” Col Vindman said.
Several Republicans on the committee, including Representative Jim Jordan of Ohio, raised concerns about Col Vindman, and pointed to statements by some of his former colleagues expressing concern about his work. Col Vindman responded by reading the career review that Ms Hill had written about his performance at the NSC.
“Alex is a top 1 per cent military officer and the best army officer I’ve worked in my 15 years of government service,” Col Vindman cited Ms Hill as saying. “He is brilliant, unflappable and exercises excellent judgment.”
The hearing was punctuated with a few light moments, including when Col Vindman was asked what languages he spoke. “I speak Russian and Ukrainian — and a little bit of English,” he said to laughter.
The Purple Heart recipient confirmed that a Ukrainian official had asked if he would serve as Ukraine’s defence minister. “I’m an American. I came here when I was a toddler,” he said. “I immediately dismissed these offers and did not entertain them.”
Asked if he was a “Never Trumper”, Col Vindman said he was a “Never Partisan”. He said he knew he was “assuming a lot of risk” by testifying, but stressed that he was confident that he had taken the right decision.
“This is America. This is the country I’ve served and defended, that all my brothers have served. And here, right matters,” he said, sparking loud applause.
Follow Demetri Sevastopulo on Twitter: @dimi