President Trump on Wednesday lashed out at The New York Times in a tweet over the paper's publishing an op-ed by an anonymous Trump administration official.

Hours after the piece was published, Trump questioned whether the official exists and demanded that the paper turn the author over to the government, saying it is a national security issue.

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

Trump in an earlier tweet appeared to question earlier Wednesday whether the official had committed "TREASON" by writing the piece.

The op-ed was written by an anonymous source claiming to be part of the "resistance" inside the Trump administration. The individual describes in the piece internal efforts among aides and Cabinet officials to combat Trump's "misguided impulses."

The blistering article sent shockwaves through Washington and frustrated the administration.

The Times published the piece along with an editor's note stating that the person's identity was known to the Times, and that publishing the column anonymously was "the only way to deliver an important perspective to our readers."

White House press secretary Sarah Huckabee Sanders also ripped the individual who wrote the piece, calling him or her a "coward" and saying they should "do the right thing and resign."

Trump in a tweet late Wednesday said he is "draining the Swamp," but that "the Swamp is trying to fight back."

--This report was updated on Sept. 6 at 7:05 a.m.