The unknown writer behind a famous 2018 op-ed also said other administration officials were "considering adding their voices before votes are cast in 2020."
The president has repeatedly maligned the Cold War-era alliance, even suggesting the pact is obsolete.
The claim is made in the exposé "A Warning," the book by an anonymous senior official in the Trump administration.
The anonymous author of a new book—"A Warning"—claimed the president keeps staffers in line by fostering an environment where they could lose their jobs at any moment.
Did Donald Trump lie to Robert Mueller? Impeachment investigators want to know.
The president publicly backed Crown Prince Mohammed bin Salman in the aftermath of the killing despite evidence of his involvement.
Former White House Press Secretary Anthony Scaramucci appeared on CNN to discuss the book "A Warning" and suggested Trump is senile.
Rick Wiles' new conspiracy theory claims former president Barack Obama is the voice hiding behind the Anonymous author of the book 'A Warning.'
The unnamed author of "A Warning," an exposé of President Donald Trump's White House, claims to be a senior administration official.
Speaking at a Trump rally in Kentucky, Sen. Rand Paul claimed to know the identity of the whistleblower and called on the media to unmask them.
The winner waited 132 days before claiming the largest jackpot payout to a single person in U.S. history.
A nursing assistant anonymously describes five months of shame allegedly conducted by co-workers and superiors at the Gardens for Memory Care in Easton, Pennsylvania.
President Donald Trump told reporters Friday that he wanted Attorney General Jeff Sessions to investigate the identity of the senior administration official behind the anonymous New York Times op-ed essay published this week as he considered legal action against the paper.
If some in the White House believe that working "behind the scenes is a consolation, I don't think it's good enough," Pelosi said.
A gaggle of senior White House officials are rushing to deny writing the anonymous New York Times op-ed that scathingly portrayed President Donald Trump.
"We will not sit idly by while you take advantage of the misinformed," the hacker group proclaimed.
Andrew Anglin's website has been blocked by GoDaddy, Google and others following its comments on the Charlottesville violence.
"Our campaign will not stop until your ideology of hate is dead and buried forever," the hacktivist collective said, launching its first large-scale operation in years.
Scaramucci said the president told him it wasn't certain Russia meddled in election.
Fox News has again defended President Donald Trump and his administration, but won't name writers or sources.
The hacking collective Anonymous had claimed that NASA was on the verge of announcing that it had found alien life forms.
The hacking collective says that NASA is about to announce that we are not alone. But things aren't quite that simple.
Online activist group Anonymous is urging viewers to "prepare for what comes next" as tensions between President Donald Trump and North Korea heat up.
But McAfee tells Newsweek he would not be Trump's cyber chief if offered the role.