An NBC News report claiming President Trump requested a tenfold increase in the U.S. nuclear arsenal is "absolutely false," Defense Secretary Jim Mattis said in a Wednesday statement.

"Recent reports that the President called for an increase in the U.S. nuclear arsenal are absolutely false," Mattis said. "This kind of erroneous reporting is irresponsible."

Minutes earlier, Trump told reporters in the Oval Office that the report was "fake news" and that such an increase was "totally unnecessary." He added that he wants the U.S. arsenal to be in "tip-top shape" and "perfect shape."

"General Mattis put out a statement, or is putting out a statement, saying that was fake news, that it was just mentioned that way." He also said it's "disgusting" that the media can write what it wants.

The NBC News story, published early Wednesday morning, said Trump's request occurred during a meeting at the Pentagon July 20, after Trump was showed a briefing slide illustrating the reduction of nuclear stockpile since the 1960s.

"According to the officials present, Trump's advisers, among them the Joint Chiefs of Staff and Secretary of State Rex Tillerson, were surprised," the story said. "Officials briefly explained the legal and practical impediments to a nuclear buildup and how the current military posture is stronger than it was at the height of the buildup. In interviews, they told NBC News that no such expansion is planned."

After this meeting broke up, Tillerson is reported to have called Trump a "moron," but it's unclear if he was referring to the nuclear question or some other item that came up during the long and often tense meeting.

Trump's comments that a buildup is "unnecessary" seem to run counter to a tweet from December, in which he said "The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes."