President Trump said Friday said he wants Attorney General Jeff Sessions to investigate the identity of the U.S. official who wrote an anonymous op-ed criticizing Trump that was published in the New York Times on Wednesday.

“It’s national security,” Trump told reporters aboard Air Force One. “I would say Jeff should be investigating who the author of that piece was because I really believe it’s national security.”

Trump added that he is looking into what actions could be taken against the New York Times, as well as the author once the administration determines who it is.

“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,” the president explained. “Supposing I have a high level national security, and he has got a clearance, we talked about clearances a lot recently, and he goes into a high level meeting concerning China or Russia or North Korea or something. I don’t want him in those meetings.”

Justice Department spokeswoman Sarah Isgur Flores told the Washington Examiner in response: "The Department does not confirm or deny investigations.”

[Also read: Here are the Trump officials denying they wrote anonymous New York Times op-ed]

The op-ed was written by an anonymous senior official in the Trump administration, and details the “resistance” inside.

“I work for the president but like-minded colleagues and I have vowed to thwart parts of his agenda and his worst inclinations,” the person wrote.

Trump said Friday that the op-ed is a “disgrace” and it is “more disgraceful” that the New York Times published it.

“For somebody to do that is very low ... Journalistically and many different standpoints, and maybe even from the standpoint of national security, we’ll find out about that,” he said.

The White House has denounced the op-ed, and numerous Cabinet officials have gone on the record to say they did not write it.

Trump also said that libel laws “should be toughened up.”

“Our libel laws are pathetic. Our libel laws should be toughened up so that if somebody writes things that are fraudulent and false, they get sued and they lose,” the president said.

The unanimous 1964 Supreme Court decision in New York Times vs. Sullivan holds that the First Amendment protects even false statements about public officials and public figures.

However, the ruling does not protect against statements made with "actual malice” — which means that the person or publication knew they were false and published the material anyway, or that the statements were published with reckless disregard to whether they were true or false.