Mr Kelly’s remark insulting the US president’s intelligence, which was confirmed to the Associated Press by a former official, comes amid increasingly virulent clashes over policy and personnel.
In a statement, Mr Kelly called the first report of his remarks by ABC News “total BS,” and characterised his relationship with Mr Trump as “incredibly candid and strong.”
Speaking of the president, he added: ”He always knows where I stand and he and I both know this story is total BS.”
Apparently responding to the report on Twitter, Mr Trump attacked the media for what he said was “fake news” and called them “truly bad people!”
“The Fake News is going crazy making up false stories and using only unnamed sources (who don’t exist),” he said.
“They are totally unhinged, and the great success of this Administration is making them do and say things that even they can’t believe they are saying. Truly bad people!”
He added: “The White House is running very smoothly despite phony Witch Hunts etc. There is great Energy and unending Stamina, both necessary to get things done.
“We are accomplishing the unthinkable and setting positive records while doing so! Fake News is going ‘bonkers!’”
In recent months, Mr Trump has chafed at Mr Kelly’s management style, and has reportedly talked with friends about replacing him.
During his early days in the White House, Mr Kelly imposed strict controls on access and the flow of information to Mr Trump.
The disagreements between the retired four-star general and the businessman-turned-president have grown more animated, and on one such occasion last year Mr Kelly blasted the president as “an idiot” to staffers, the former administration official told the Associated Press.
Kelly has also told confidants that he has at times served as a guardrail, protecting the American people from Trump, another person familiar with his told the AP.
Such a public revelation of an insult directed at the president’s intelligence is reminiscent of leaks last year, when the secretary of state at the time, Rex Tillerson, reportedly called Mr Trump a “moron.”
The episode created what White House officials described as an irreparable rift between Mr Trump and his chief diplomat and ultimately led to Mr Tillerson’s being unceremoniously fired in March.
Mr Kelly said NBC’s report “is another pathetic attempt to smear people close to President Trump and distract from the administration’s many successes.”
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