Reporter outs source of White House background briefing after Trump complains he 'doesn't exist'

President Donald Trump lashed out at The New York Times on Saturday, denying a report citing an official White House briefing.

ABC News correspondent Alex Mallin quickly de-bunked Trump's claims.

Reporters for the newspaper, which Trump referred to as "failing and corrupt" in an earlier Saturday morning, were shocked that the president would make such a claim.

"Imagine being the WH background briefer who led this briefing, who now has his boss - the president of the US - saying he/she doesn’t exist," reporter Maggie Haberman suggested.

"The president of the United States is now claiming that his own White House briefings are fake news and that an official his White House put in the briefing room 'doesn't exist,'" noted Peter Baker.

Reporters at other publications also joined in to scorn the White House.

"Doesn’t seem like there’s any reason to honor WH demands for anonymous briefings if the WH is going to then claim their own briefings are fake news," argued NBC News reporter Benjy Sarlin.

One reporter went even further, outing the "senior White House official" who conducted the background briefing.

Yashar Ali, who writes for New York Magazine and the Huffington Post, revealed the official to be Matt Pottinger, who serves on the National Security Council.

Ali clarified that he was not bound by the background agreement.

"To be clear, the only reason I tweeted Matt's name is because I'm not a White House reporter and I was not on this call," he explained. "Not my agreement, so I can tweet."