Washington (CNN) President Donald Trump believes the author of an anonymous op-ed criticizing his leadership and detailing a "resistance" within his administration is "somebody in national security," Kellyanne Conway said on Friday.

"The President just, just today said he believes it's somebody in national security," Conway told CNN's Christiane Amanpour in an interview for her new hour-long program, which premiers on CNN International and PBS on Monday.

Conway said she doesn't believe the unnamed senior administration official who wrote The New York Times op-ed is a White House official but said the person "ought to come forward and say it, or ought to resign because the loyalty is not to the President, or at all, it's loyalty to the presidency."

The op-ed penned by an anonymous senior administration official on Friday has rattled the President and the White House, sending White House officials on a search to unmask the official in question.

Trump has repeatedly assailed the author as a "coward" and "gutless," and called on The New York Times to release the author's identity.

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