The former secretary of state told Cooper that the country is experiencing a "constitutional crisis" following Bob Woodward's new book, which depicts the Trump administration and the White House as dysfunctional and completely unhinged.
President Trump reacted for the first time Wednesday to an op-ed The New York Times published from someone identified only as a senior administration official, who says they are part of the "resistance" holding back the president's "half-baked, ill-informed and occasionally reckless decisions".
The book quotes Kelly as having doubts about Trump's mental faculties, declaring during one meeting, "We're in Crazytown".
Mr Woodward's much-awaited book, Fear: Trump In The White House, shows aides routinely ignoring or acting to block orders by the US President.
Defence Secretary Jim Mattiss also released a statement on the quotes attributed to him which said Trump had the understanding of a 'fifth or sixth grader'.
And in April 2017, after Syria's Bashar al-Assad attacked civilians with chemical weapons, Mr Woodward reports, Trump demanded Mr Mattis assassinate Mr Assad.
Mattis said he'd 'get right on it, ' but ordered limited airstrikes that didn't threaten Assad personally instead.
"While I generally enjoy reading fiction, this is a uniquely Washington brand of literature, and his anonymous sources do not lend credibility", Mattis said in the statement.
President Trump described Attorney General Jeff Sessions as a "traitor" and "mentally retarded" to aides, according to an explosive new book by veteran journalist Bob Woodward. He's gone off the rails.
Seth Meyers dedicated some of his monologue to the upcoming release, referring to a recorded conversation between the president and journalist regarding the book: "He's like a guy who doesn't understand he's being dumped".
"It's just another bad book", Trump told the Daily Caller.
- The president after making a speech condemning white supremacists over violence in Charlottesville: "That was the biggest f****** mistake I've made".
"There is no federal libel law for President Trump to bully Congress to change, and the president does not have the authority to change state libel laws", Hauss said.
The White House did not immediately respond to Business Insider's request for comment on the book.
Trump says he would have liked to speak with Woodward and he says it sounds like it will be a "negative" book.
Trump claimed that the quotes in Woodward's book were "made up frauds, a con on the public". She told reporters at United Nations headquarters that she had been privy to conversations about the Syrian chemical weapons attacks, "and I have not once ever heard the president talk about assassinating Assad".
"I don't even know why any of us are here. He (Trump) is also denying it, by the way", Israeli Intelligence Minister Israel Katz told Tel Aviv radio station 103 FM.
Entitled "Fear: Trump in the White House,"the Woodward book is scheduled to be released September 11".
Trump also called Sessions was a "traitor" for from the special counsel Robert Mueller's Russian Federation investigation, according to the Washington Post, which reviewed a copy of the book.
Mattis' statement follows a pair of denials from the White House regarding Woodward's book. "Notice timing?" he added, after tweeting earlier statements by Defense Secretary James Mattis, White House Chief of Staff John Kelly and spokeswoman Sarah Sanders refuting the quoted statements as false. I think Sessions is a very smart man and a man of integrity.
The White House hit back at "fabricated stories" as the long-awaited book piled fresh pressure on a president besieged by multiple investigations and a looming election that could damage his Republican Party.