Former national security advisor John Bolton will defy the White House and publish a book that suggests President Donald Trump committed impeachable offenses beyond Ukraine, his publisher said Friday.

Trump earlier this year had warned that Bolton should not publish his book while the president is still in the White House, whose lawyers have reportedly contended that large portions of the material in the memoir is classified.

But publisher Simon and Schuster said it would go ahead and publish "The Room Where It Happened: A White House Memoir" on June 23, teasing in a press release: "This is the book Donald Trump doesn't want you to read."

"I am hard-pressed to identify any significant Trump decision during my tenure that wasn't driven by re-election calculations," Bolton writes in the book, according to the release.

The publisher said that Bolton will document wrongdoing by Trump that goes beyond his pressure on Ukraine to investigate Democratic rival Joe Biden -- which triggered his impeachment by the Democratic-led House of Representatives.

Bolton "argues that the House committed impeachment malpractice by keeping their prosecution focused narrowly on Ukraine when Trump's Ukraine-like transgressions existed across the full range of his foreign policy," the publisher said.

Bolton will describe Trump's "inconsistent, scattershot decision-making process," it said.

Bolton, a veteran Republican policymaker known for his hawkish views, left in September after disagreeing with Trump's diplomatic outreach to adversaries, notably North Korea.

The memoir will renew questions on why Bolton, if he believed Trump had committed such serious offenses, did not testify as part of his impeachment and instead waited to sell his book.

Chuck Schumer, the Democratic leader in the Senate, where Trump was acquitted, said during the trial that Bolton's testimony could help persuade wavering Republicans to remove Trump from office.

Bolton, who favors a tough line on Russia, was known to have opposed the White House's freeze on $400 million in military aid to Ukraine as it battled separatists backed by Moscow.

Trump in a phone call to Ukrainian President Volodymyr Zelensky had pressed him to dig up dirt on Biden over the former vice president's son's business dealings in the country.

Trump has called the impeachment a conspiracy against him, contending his pressure on Ukraine was in the larger US interest.