Journalist Bob Woodward claims President Donald Trump has said clarification of his "both sides" speech after the Charlottesville white supremacist rally was the "worst speech" he's "ever made."

Trump told aides that condemning white supremacists and neo-Nazis was the "biggest f—-ing mistake" he's made, Woodward wrote in his new book "Fear: Trump in the White House."

The "both sides" speech led former top economic adviser Gary Cohn to threaten to resign, according to Woodward.

Cohn was accused of "treason" by Trump when he tried to hand in his resignation papers and was persuaded to stay on staff, Woodward wrote.

President Donald Trump said that clarifying his "both sides" speech after the deadly white supremacist rally in Charlottesville, Virginia, last year was the "biggest f---ing mistake" he has made, according to an upcoming book from renowned journalist Bob Woodward.

Two days after the death of a young woman protesting the white supremacist rally in Charlottesville in August 2017, Trump spoke about the incident during an impromptu news conference in New York.

His comments were widely criticized by people who said Trump did not specifically condemn white nationalists and neo-Nazis, and the president's aides immediately urged him to clarify his statements.

Trump eventually made another speech and condemned white supremacists and neo-Nazis.

But according to Woodward's forthcoming book "Fear: Trump in the White House," which has been seen by The Washington Post, Trump said he believes that his condemnation was the "worst speech" he's ever made.

Trump's "both sides" comments led former top economic adviser Gary Cohn to threaten to resign, according to Woodward.

Cohn, who is Jewish and was left shaken after one of his daughters found a swastika on her college dorm room, was accused of "treason" by Trump when he tried to hand in his resignation papers and was persuaded to stay on staff, Woodward wrote.

Woodward wrote that White House chief of staff John Kelly shared Cohn's worries over Trump's handling of the incident.

"I would have taken that resignation letter and shoved it up his a-- six different times," Kelly told Cohn, according to Woodward.

In "Fear," Woodward, a Pulitzer Prize-winning journalist who blew open the Watergate scandal and wrote probing looks into the Obama and Bush administrations, promises to bring readers "face-to-face" with the Trump administration.

Sources told CNN that the book, which comes out on September 11, is based on hundreds of hours of taped interviews with first-hand sources who will examine Trump's role in the White House.

The White House responded later Tuesday to the book.

“This book is nothing more than fabricated stories, many by former disgruntled employees, told to make the President look bad," said Press Secretary Sarah Sanders in a statement.

White House chief of staff John Kelly decried "Fear" as “another pathetic attempt to smear people close to President Trump and distract from the administration’s many successes."