“I would say [Attorney General Jeff Sessions] should be investigating who the author of this piece was because I really believe it’s national security,” Trump told reporters on Air Force One.

While the author of the op-ed did not reveal any classified information, instead focusing on the White House’s inner workings, Trump’s latest comments seem to hint he believes the article is worthy of a criminal investigation.

“We’re going to take a look at what he had, what he gave, what he’s talking about, also where he is right now,” said Trump, adding that he doesn’t want the author involved in important meetings if the author has a high security clearance.

The op-ed, published Wednesday, accuses the president of behaving in “a manner that is detrimental to the health of our republic” and says he or she is a part of a network of aides “working diligently from within to frustrate parts of [Trump’s] agenda and his worst inclinations.”

Trump claims that his call for an investigation is not spurred by the op-ed’s negative portrayal of him.

“I don’t mind criticism, I handle it, and I fight back,” said Trump, according to CNN. “But here’s criticism where you can’t fight back. ‘Cause you have somebody doing it anonymously.”

On Twitter, Trump has called the author “gutless” and called for the Times to turn over their contact “for National Security purposes.”

Does the so-called “Senior Administration Official” really exist, or is it just the Failing New York Times with another phony source? If the GUTLESS anonymous person does indeed exist, the Times must, for National Security purposes, turn him/her over to government at once!

— Donald J. Trump (@realDonaldTrump) September 5, 2018

Trump also called the Times op-ed publication a “disgrace,” CNBC reports, adding that “for somebody to do this is very low, and I think, journalistically and from many different standpoints, and maybe even from the standpoint of national security.”