WASHINGTON — The White House told former national security advisor John Bolton that a book he has written reportedly containing damaging evidence for President Donald Trump cannot be published in its current form because it breaks secrecy laws.

The warning was made in a letter to Bolton's lawyer dated January 23 but only made public on Wednesday as Trump's impeachment trial intensified in the Senate.

The National Security Council said after preliminary review of the manuscript – a vetting process applied to any White House employees writing books – that it contained "significant amounts of classified information."

"Some of this information is at the TOP SECRET level," the NSC said in a letter to Bolton's lawyer Charles Cooper, adding that "the manuscript may not be published or otherwise disclosed without the deletion of this classified information."

Bolton's lawyer pushed back at the White House claims in a letter sent the next day, which he also made public on Wednesday.

"We do not believe that any of that information could reasonably be considered classified," Cooper wrote.

Democrats are pressing for the Senate to subpoena Bolton after reports that his White House memoir "The Room Where it Happened" corroborates the key abuse-of-power impeachment charge against Trump.

Bolton reportedly writes that the president personally told him in August that a freeze in military aid to Ukraine was directly linked to Trump's demand that Kiev announce investigations into Joe Biden, the frontrunner for the Democratic presidential nomination.

In his letter, Cooper asks the NSC to rapidly conclude its review of the manuscript, in light of the possibility Bolton may be subpoenaed to appear at Trump's trial.

"If he is called to testify, it seems certain that he will be asked questions that will elicit much of the information... dealing with his involvement in matter relating to Ukraine," wrote Cooper, who said he had received no response as of Wednesday.

Several hours before the NSC letter went public, Trump lashed out at Bolton on Twitter, saying he had written a "nasty & untrue book. All Classified National Security."

Despite the formal review process of Bolton's book, drafts have already circulated around Washington, where the passages describing Trump's relationship with Ukraine caused a sensation.

At a news conference in Davos last week, Trump indicated he was worried about Bolton, whom he fired in 2019.

Trump said the veteran foreign policy advisor "knows some of my thoughts. He knows what I think about leaders. What happens if he reveals what I think about a certain leader and it's not very positive?" — AFP