Trump branded Comey weak, a "LEAKER & LIAR" and an untruthful "slime ball" in a two-part Twitter tirade, as the first reports of the ex-FBI boss' highly critical 300-plus-page book emerged.
Comey is scheduled to make numerous media appearances for his book starting Sunday.
The book is due to be released on Tuesday, but Comey has already appeared on television to promote it and the White House has been strategising for weeks about how to discredit it. Officials responded to the Wolff book by belatedly pointing out factual inaccuracies.
And White House counselor Kellyanne Conway said Comey "has a revisionist view of history and seems like a disgruntled ex-employee".
Sanders is accusing Comey of leaking classified information and breaking his "sacred trust with the president of the United States, the dedicated agents of the Federal Bureau of Investigation, and the American people". Comey went on to deliver his testimony before the Senate Intelligence Committee, where he accused the President of lying about their interactions.
Comey's no holds barred account of his meetings with Trump before he was sacked at times appears mean spirited, but also conveys a sense of disbelief about the 45th president's behavior. McCabe has suggested that Comey authorized the leak _ a claim disputed in the independent inspector general report, which says McCabe allegedly misled Comey about the disclosure.
Earlier on Friday, Trump also tried to knock down Comey's book and defended his decision to fire him. "No collusion, all made up by this den of thieves and lowlifes!"
White House press secretary Sarah Sanders also attacked Comey's credibility on Friday, saying that even Democrats don't trust him.
"This is nothing more than a poorly executed PR stunt by Comey to desperately rehabilitate his tattered reputation and enrich his own bank account by peddling a book that belongs in the bargain bin of the fiction section instead of being remembered as a dedicated servant in the pursuit of justice", she continued.
News organisations obtained copies of the manuscript, in which Comey portrays Trump as an egomaniac - "unethical, and untethered to truth and institutional values".
Comey's new book, which focuses on the former Federal Bureau of Investigation director's brief stint at the agency before Trump fired him, is filled with significant accusations and criticisms aimed at Trump.
The president repeated his belief that Comey deserved to be fired and expressed confidence the American public "would see through his lies" and realize Comey was part of a "deep state" effort to undermine the administration.