President Donald Trump lashed out at the former U.S. ambassador to Ukraine as she testified on Friday morning in the House impeachment hearings.

Marie Yovanovitch, who was removed from her post in May, testified that foreign policy toward Ukraine had come under the sway of foreign corrupt interests.

She said she felt personally threatened by the president’s reference to her in a July 25 phone call with Ukraine President Volodymyr Zelensky, in which the president said she was “bad news” and was going to “go through some things.”

“I was absolutely shocked and devastated, frankly,” Yovanovitch said. “It was a terrible moment. … It didn’t sound good. It sounded like a threat.”

As she was testifying, Trump tweeted an attack on Yovanovitch, saying he had every right to remove her.

“Everywhere Marie Yovanovitch went turned bad,” Trump tweeted. “She started off in Somalia, how did that go?”

Adam Schiff, the chairman of the Intelligence Committee, took note of Trump’s comment during the hearing and asked Yovanovitch to respond.

“I don’t think I have such powers,” she said, adding that she and other diplomats “have demonstrably made things better for the U.S.”

Yovanovitch added that Trump’s attacks are “very intimidating.”

When the committee went into a recess, Schiff said the president was trying to intimidate witnesses in the hearing.

“We saw today witness intimidation in real time by the president of the United States, in an effort not only to chill her, but to chill others who may come forward,” he said.

Yovanovitch served as ambassador from August 2016 to May 2019. In her opening statement, she spoke about U.S. policy efforts to combat corruption in the country. She said her efforts were undermined by a smear campaign against her led by Rudy Giuliani, the president’s personal lawyer.

“The attacks are leading to a crisis in the State Department as the policy process is visibly unravelling,” she said. “The State Department is being hollowed out from within at a competitive and complex time on the world stage.”