Two top national security aides who listened to President Donald Trump's call with Ukraine are preparing to testify in the Washington impeachment hearings, launching a week of back-to-back sessions.
Lieutenant Colonel Alexander Vindman, attached to he National Security Council, and Jennifer Williams, his counterpart at Vice President Mike Pence's office, say they had concerns as Trump spoke on July 25 with Ukraine's newly-elected president about political investigations into Joe Biden.
After they appear on Tuesday morning, the House will hear in the afternoon from former NSC official Timothy Morrison and Kurt Volker, the former Ukraine special envoy.
In all, nine current and former US officials are testifying in a pivotal week as the House's historic impeachment inquiry accelerates and deepens.
Democrats say Trump demanded Ukraine investigate his Democratic rivals in return for US military aid it needed to resist Russian aggression and that may be grounds for removing the 45th president.
Trump says he did no such thing and the Democrats just want him gone.
"I did not think it was proper to demand that a foreign government investigate a US citizen," said Vindman, an Iraq War veteran.
He said there was "no doubt" what Trump wanted from Ukrainian President Volodymyr Zelenskiy.
It wasn't the first time Vindman, a 20-year military officer, was alarmed over the administration's push to have Ukraine investigate Democrats, he testified.
Earlier, during an unsettling July 10 meeting at the White House, Ambassador Gordon Sondland told visiting Ukraine officials they would need to "deliver" before next steps, which was a meeting Zelenskiy wanted with Trump, the officer testified.
"He was talking about the 2016 elections and an investigation into the Bidens and Burisma," Vindman testified, referring to the gas company in Ukraine where Hunter Biden served on the board.
"The Ukrainians would have to deliver an investigation into the Bidens," he said. "There was no ambiguity."
On both occasions, Vindman said, he took his concerns about the shifting Ukraine policy to the lead counsel at the NSC, John Eisenberg.
Williams, a longtime State Department official detailed to Pence's national security team, said she too had concerns during the phone call, which the aides monitored as is standard practice.
When the White House produced a transcript later that day, she put it in the vice president's briefing materials. "I just don't know if he read it," Williams testified in camera.
Sondland, the wealthy donor whose routine boasting about his proximity to Trump has brought the investigation to the president's doorstep, will testify Wednesday.
Others have testified he was part of a shadow diplomatic effort with the president's personal lawyer, Rudy Guiliani, outside of official channels that raised alarms.
Pence's role throughout the impeachment inquiry has been unclear.
The White House has instructed officials not to appear and most have received congressional subpoenas to compel their testimony.
Those doing so have already given closed-door interviews and transcripts from those depositions have largely been released.
Australian Associated Press