(CNN) President Donald Trump is denying White House chief of staff John Kelly is suffering from diminished credibility and influence following a Washington Post report Saturday on Kelly's recent struggles.

"Story on John Kelly isn't true, just another hit job!" Trump wrote in a Sunday tweet that claimed the newspaper produces "far more fiction than fact."

Trump frequently criticizes the Post and other major news outlets, claiming their reports are untrue. His tweet Sunday morning was deleted and then re-published with a correction to a typo.

The Post reported Trump has started to bypass Kelly , who has sought to control access to the President in a variety of ways. CNN has previously reported on tensions between the President and his chief of staff, including the fact that Kelly has threatened to quit in the midst of clashes with Trump, according to people familiar with the incidents.

In one incident, the Post reports, Kelly threatened to resign in a heated argument with Trump where he attempted to dissuade the President from firing former Secretary of State Rex Tillerson. But Kelly has told allies that he believes it is his duty to help implement the President's agenda.

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