President Donald Trump suggested Wednesday that the anonymous senior official who penned a New York Times op-ed was guilty of treason.

“TREASON?” Trump asked on Twitter, after publicly denouncing the author as “gutless.”

The author of the op-ed complained about “instability” from Trump in the White House, reporting that there were “whispers” in the cabinet as they considered invoking the 25th Amendment to oust the president.

Trump challenged the New York Times to give up the identity of the author for the purpose of national security.

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

White House press secretary Sarah Sanders called for the author of the op-ed to resign, in a statement sent to reporters.

“The individual behind this piece has chosen to deceive, rather than support, the duly elected President of the United States,” she wrote. “He is not putting country first, but putting himself and his ego ahead of the will of the American people. This coward should do the right thing and resign.”

Does the so-called “Senior Administration Official” really exist, or is it just the Failing New York Times with another phony source? If the GUTLESS anonymous person does indeed exist, the Times must, for National Security purposes, turn him/her over to government at once! — Donald J. Trump (@realDonaldTrump) September 5, 2018