Donald Trump nearly managed to set off a war on the Korean peninsula with one tweet, according to veteran reporter Bob Woodward's new book Fear: Trump in the White House.

"He drafts a tweet saying ‘We are going to pull our dependents from South Korea – family members of the 28,000 people there,'" Woodward told CBS.

However, before Trump could send the tweet, word came from North Korea via a back channel that Kim's regime would take the removal of American dependents as a sign that an attack on North Korea was in the offing. That in itself could have been enough for things to kick off on the Korean peninsula, given how much weaponry North Korea has pointed across the demilitarised zone at the border with South Korea.

"At that moment there was a sense of profound alarm in the Pentagon leadership that, 'My God, one tweet and we have reliable information that the North Koreans are going to read this as ‘an attack is imminent,'" Woodward went on.

Trump has continued to lash out against claims in Woodward's book, attacking the "totally phony quotes" which have been trailed ahead of the book's release. "I mean, totally, like, fraudulent books," Trump told a rally on Friday. "They're, like, fraudulent books!"

Woodward says he has multiple sources for every claim in Fear, interviewing more than 100 sources during his research.