Former senior senior advisor to President Donald Trump’s 2020 campaign Jason Miller walks the halls of the U.S. Capitol on the first day of Trump’s second Senate impeachment trial on February 9, 2021 in Washington, DC

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Longtime advisor to former President Donald Trump and current spokesman Jason Miller is leaving his role, a source familiar with the plans told CNBC on Thursday.

Miller, who has worked for Trump since his 2016 presidential campaign, is leaving his full-time duties as former president’s spokesman to become CEO of a technology start-up, the source said without giving further details.

No start date or transition schedule has been announced, and no announcement is forthcoming, the source said.

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According to the source, however, the unnamed company owns a social media platform that Trump is “considering”.

Miller will be the first CEO of the tech company, which has had a platform in development since last year, the source said when asked for more information about the startup. Miller will nonetheless remain in Trump’s orbit and remain an ally of Trump’s team, the source said.

It is unclear who will fill the soon vacant position. Margo Martin, another Trump spokeswoman, referred CNBC to Miller for comment.

Miller’s departure comes a little over a week after Trump’s personal blog page, which was active for less than a month, was permanently closed.

This website was originally billed as a “communications platform” but in reality served only as a place for Trump to post statements that he was not allowed to share on more popular social media sites.

Miller told CNBC at the time that the blog “wasn’t going back” and that it was “just an aid to the wider effort we have and are working on.”

The spokesman also tweeted on June 2 that Trump will actually join another social media platform.

Miller had worked on Trump’s 2016 campaign and transition to president, and was originally supposed to be White House communications director for the new administration.

These plans were abandoned after allegations of an extramarital affair with former Trump campaigner AJ Delgado became public.

The Trump campaign in 2020 hired Miller for the final leg of the race that Trump lost to current President Joe Biden.