Stephen Miller slammed Steve Bannon, a former ally in the White House.

Miller dismissed Bannon's contributions to the administration.

Bannon on Sunday apologized for his remarks.

Senior policy adviser Stephen Miller was just the lastest figure to throw former ally Steve Bannon under the bus over comments he made in Michael Wolff's explosive new book on President Donald Trump's campaign and administration, "Fire and Fury."

Bannon has been the subject of intense criticism from Trump allies following his criticism in Wolff's book of Donald Trump Jr. and Ivanka Trump's intelligence, as well as his claim that a meeting between a Russian lawyer and top Trump campaign officials in 2016 was "treasonous."

During a heated interview on CNN on Sunday, Miller repeatedly attempted to dismiss Bannon's White House contributions, calling the former chief strategist's comments "grotesque" and "so out of touch with reality and obviously vindictive."

"It reads like an angry, vindictive person spouting off to a highly discredible author," Miller said.

CNN host Jake Tapper noted that Bannon influenced many key issue areas, lobbying the president to pull the US out of the multinational Trans-Pacific Partnership trade agreement, and urging him to take hard-line stances on immigration.

"Is it really the position of the Trump White House that Steve Bannon had nothing to do with the presidency?" Tapper asked. "Or can you acknowledge the reality that he was a key player?"

"I think that what the point is, is that his role has been greatly exaggerated," Miller replied. "Whereas the president hasn't gotten the due that he deserves for the movement that he put together to tap into the kinds of people whose life concerns don't get a lot of attention on CNN."

Once reportedly referred to by Trump as "my two Steves," Bannon and Miller were initially viewed as allies on the campaign and in the White House, pushing for Trump to take hard-line stances on issues like immigration.

But Miller repeatedly distanced himself from Bannon during his time in the White House, working closely with Bannon foes Jared Kushner and Ivanka Trump on several issue areas, and reportedly taking issue with Bannon's self-promotion and combative style.

"He made it clear he isn’t a Bannon guy," one White House adviser told Politico.

Bannon offered a lengthy apology on Sunday, saying he was not accusing Trump Jr. of committing treason by meeting with a Russian lawyer.

"I am the only person to date to conduct a global effort to preach the message of Trump and Trumpism; and remain ready to stand in the breach for this president's efforts to make America great again," Bannon said.

He continued:

"My comments about the meeting with Russian nationals came from my life experiences as a Naval officer stationed aboard a destroyer whose main mission was to hunt Soviet submarines to my time at the Pentagon during the Reagan years when our focus was the defeat of 'the evil empire' and to making films about Reagan's war against the Soviets and Hillary Clinton's involvement in selling uranium to them."

"My comments were aimed at Paul Manafort, a seasoned campaign professional with experience and knowledge of how the Russians operate. He should have known they are duplicitous, cunning and not our friends. To reiterate, those comments were not aimed at Don Jr."