On Sunday, National Security Adviser Robert O’Brien said Lt. Col. Alexander Vindman, who gave a bombshell testimony in the House impeachment investigation last month on President Donald Trump’s Ukraine scheme, will be removed from his post at the White House National Security Council.

“Lieutenant Colonel Vindman, who has testified under oath, is serving on the National Security Council currently,” CBS News’s “Face the Nation” host Margaret Brennan said during her interview with O’Brien. “Will he continue to work for you despite testifying against the President?”

“Well look, one of the things that I’ve talked about is that we’re streamlining the National Security Council,” O’Brien replied. “It got bloated to like 236 people up from 100 in the Bush administration under President Obama.”

The national security adviser said Vindman, who currently serves as the council’s Director for European Affairs, will be removed as a part of the White House’s “streamlining” efforts.

“My understanding is he’s–that Colonel Vindman is detailed from the Department of Defense,” O’Brien said. “So everyone who’s detailed at the NSC, people are going to start going back to their own departments and we’ll bring in new folks.”

When Brennan asked O’Brien to confirm that the decision is not retaliation against Vindman, whom Trump has baselessly accused of being a “Never Trumper,” the national security adviser’s response was that he personally had never retaliated against anyone.

“I never retaliated against anyone,” he said. “There- there will be a point for everybody who’s detailed there—that their time, that their detail will come to an end.”

As the NSC’s expert on Ukraine who was also on Trump’s call with the Ukrainian president in July, Vindman provided key information to House impeachment investigators on Trump’s use of American foreign policy to obtain political assistance from Ukraine.

Trump has attacked him and other witnesses amid the investigation, baselessly claiming that they are “Never Trumpers.” Last week, Trump threatened to release information on Vindman “real soon” that supposedly proves that the colonel is anti-Trump.

Watch O’Brien below: