The lawsuit is expected to be filed in the coming days and could come as soon as today, sources said, cautioning that some details are still being worked out.
Bolton, who departed the Trump administration last fall, was originally supposed to publish his book, “The Room Where It Happened,” earlier this year, but it was met with delays from the White House as the book went through a standard prepublication security review for classified information by the National Security Council.
Speaking to reporters on Monday afternoon, Trump said Bolton would be breaking federal law if his book is published in its current form.
“I will consider every conversation with me as president highly classified," Trump said. "So that would mean that if he wrote a book, and if the book gets out, he’s broken the law. And I would think that he would have criminal problems, I would hope so.”
“They’ll soon be in court,” Trump added.
Sitting beside the president, Attorney General Bill Barr said the Justice Department is focused on ensuring that Bolton makes "the necessary deletions of classified information." Barr called Bolton's book "unprecedented."
"I don’t know of any book that's been published so quickly while the officeholders are still in government, and it’s about very current events, current leaders and current discussions of current policy issues, many of which are inherently classified," Barr said.
In a description of the coming book, Bolton’s publisher says, “What Bolton saw astonished him: a President for whom getting reelected was the only thing that mattered, even if it meant endangering or weakening the nation.”
According to the description, posted online, Bolton details potentially impeachment-worthy “transgression” across “the full range” of Trump’s foreign policy.
Bolton's first interview about the memoir, with ABC News Chief of Global Affairs Correspondent Martha Raddatz, is set to air in a one-hour special Sunday, June 21 at 9 p.m. ET on the ABC Television Network.
The NSC and Bolton’s team have been at odds about the information in the manuscript, according to letters exchanged between the two and provided to ABC News by Bolton’s attorney, Chuck Cooper, and the White House.
The NSC claimed the book continued to contain “significant amounts” of classified information, but Bolton’s lawyer pushed back, claiming that none of it “could reasonably be considered classified.”
In a Wall Street Journal op-ed last week, Cooper wrote that on June 8 White House lawyer John Eisenberg “asserted in a letter that Mr. Bolton’s manuscript contains classified information and that publishing the book would violate his nondisclosure agreements.”
“This last-minute allegation came after an intensive four-month review, after weeks of silence from the White House, and -- as Mr. Eisenberg admits in his letter -- after press reports alerted the White House that Mr. Bolton’s book would be published on June 23,” Cooper wrote.
"This is a transparent attempt to use national security as a pretext to censor Mr. Bolton, in violation of his constitutional right to speak on matters of the utmost public import," he wrote. "This attempt will not succeed, and Mr. Bolton’s book will be published June 23.”
In a related press release, the publisher said that in the weeks before Bolton's book was printed, Bolton worked with the NSC to address NSC's concerns, and the "final, published version of this book reflects those changes."
The White House and the Justice Department did not respond to a request seeking comment for this report Monday.