United States President Donald Trump has urged the Department of Justice to investigate and identify the government official who wrote an anonymous opinion-editorial (op-ed) in The New York Times criticising his administration – suggesting that the issue is a matter of national security.

Speaking to reporters on board Air Force One on Friday, the president said he was contemplating initiating action against the New York Times. He also added that White House officials are trying to identify the writer of the piece.

Trump added that Attorney General Jeff Sessions should launch an investigation.

“I think so. It’s national security. I would say Jeff should be investigating who the author of that piece was because I really believe it’s national security,” he said.

The New York Times, however, resisted Trump’s suggestion that the Justice Department track down the anonymous senior official.

“We’re confident that the Department of Justice understands that the First Amendment protects all American citizens and that it would not participate in such a blatant abuse of government power,” the newspaper said.

“The president’s threats both underscore why we must safeguard the identity of the writer of this Op-Ed and serve as a reminder of the importance of a free and independent press to American democracy,” it said.