Marie Yovanovitch, the former U.S. ambassador to Ukraine, told House impeachment investigators during a closed-door session Friday that President Donald Trump pressured the State Department to oust her after a "concerted campaign" of attacks led by Trump's personal attorney Rudy Giuliani.

"After being asked by the department in early March to extend my tour until 2020, I was then abruptly told in late April [of 2019] to come back to Washington from Ukraine 'on the next plane,'" Yovanovitch said in her opening statement to members of the House Intelligence, Oversight, and Foreign Affairs Committees, according to a copy of her remarks obtained by the Washington Post.

Read Yovanovitch's prepared statement in full here.

"I was incredulous that the U.S. government chose to remove an ambassador based, as best as I can tell, on unfounded and false claims by people with clearly questionable motives."

—Marie Yovanovitch, former U.S. ambassador to Ukraine

Yovanovitch said Deputy Secretary of State John Sullivan told her after she was recalled that Trump "lost confidence" in her and no longer wanted her to serve as ambassador to Ukraine.

"He added that there had been a concerted campaign against me, and that the department had been under pressure from the president to remove me since the summer of 2018," Yovanovitch told House investigators. "He also said that I had done nothing wrong and that this was not like other situations where he had recalled ambassadors for cause."

Yovanovitch said the "concerted campaign" of attacks was led by Giuliani and his allies, who "may well have believed that their personal financial ambitions were stymied by our anti-corruption policy in Ukraine."

"Although I understand that I served at the pleasure of the president," Yovanovitch testified, "I was nevertheless incredulous that the U.S. government chose to remove an ambassador based, as best as I can tell, on unfounded and false claims by people with clearly questionable motives."

Yovanovitch's deposition came a day after Giuliani associates Lev Parnas and Igor Fruman were arrested for their role in a vast criminal conspiracy that included funneling foreign cash to Trump with the goal of ousting Yovanovitch.

The Wall Street Journal reported earlier this month that Trump recalled Yovanovitch from her post after Giuliani and others complained that she was undermining the U.S. president and "obstructing efforts to persuade Kyiv to investigate former Vice President Joe Biden."

Rep. Ted Lieu (D-Calif.) described Yovanovitch's testimony Friday as "more damning evidence that Trump and his enablers engaged in a multi-prong campaign to get Ukraine to target Biden."

"This is why Donald Trump and Secretary of State Mike Pompeo didn't want former U.S. Ambassador Marie Yovanovitch to tell her story to the American people," Lieu tweeted. "It's a story about corruption at the highest levels of our government, including all the way up to POTUS."