White House national security adviser Robert O’Brien in an interview broadcast on Sunday denied that former acting director of national intelligence (DNI) Joseph Maguire Joseph MaguireCongressional Democrats request FBI briefing on foreign election interference efforts Wells Fargo told employees to delete TikTok from work phones Hillicon Valley: Pompeo floats TikTok ban | Civil rights groups slam Facebook after call | Election security funding included in proposal MORE was dismissed because one of his appointees briefed the House Intelligence Committee on Russian efforts to interfere in the 2020 election.

Asked by CBS’s Margaret Brennan on "Face the Nation" if he was “100 percent sure it had nothing to do with this congressional briefing,” O’Brien responded: “First of all, Joe Maguire wasn’t pushed out… he was serving under the Vacancy Act. He was acting, and his term, I believe, was ending March 11 or March 2, like two weeks from now.”

“We’re looking for a nominee that can be a terrific candidate, who can be nominated for this position. We needed someone who was Senate-confirmed, who could serve in the meantime,” O’Brien added.

WATCH: NSA Robert O'Brien says that Joseph Maguire, former acting director of national intelligence, was not pushed out following a congressional briefing on Russian efforts to influence the 2020 election.



"I have a tremendous amount of respect for him, as does the president" pic.twitter.com/6Cr6tLgqYe — Face The Nation (@FaceTheNation) February 23, 2020

The White House has tapped U.S. ambassador to Germany Richard Grenell as the new acting DNI and has said the former ambassador, who is unlikely to achieve Senate confirmation, will not serve in the role long-term.

“We’ll get a nominee out to the Senate as soon as possible,” O’Brien told CBS. “We’d love to see Joe Maguire stay involved in the government. Joe had a great relationship with the president, I had a great relationship with him. We have a lot of respect for Joe Maguire.”

Trump reportedly decided against nominating Maguire on a permanent basis after learning about the briefing by Maguire's staffer, Shelby Pierson, and, according to The Washington Post, erroneously believed she had specifically briefed Chairman Adam Schiff Adam Bennett SchiffTop Democrats call for DOJ watchdog to probe Barr over possible 2020 election influence Overnight Defense: Top admiral says 'no condition' where US should conduct nuclear test 'at this time' | Intelligence chief says Congress will get some in-person election security briefings Overnight Defense: House to vote on military justice bill spurred by Vanessa Guillén death | Biden courts veterans after Trump's military controversies MORE (D-Calif.), a frequent Trump target who served as one of the House’s impeachment managers.

Pierson reportedly told lawmakers that Russia had a "developed preference" to reelect Trump.