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WASHINGTON — President Donald Trump expressed disgust Thursday morning with the explosive whistleblower complaint, slamming the intelligence officer and the White House aides who helped him or her as “almost a spy” and suggested it was treason.

Speaking at a private event with U.S. diplomatic officials in New York, Trump described reporters as “scum” and raged at the Democrats’ new impeachment proceedings, which were spurred by the whistleblower’s complaint alleging that Trump tried to strong-arm Ukraine’s leader to interfere in the 2020 election.

The still-unidentified intelligence officer acknowledged that he did not listen to Trump’s July 25 phone call with Ukrainian President Volodymyr Zelensky, but cited accounts from more than half a dozen White House and other officials over the last four months as part of “official interagency business.”

“Basically, that person never saw the report, never saw the call, he never saw the call — heard something and decided that he or she, or whoever the hell they saw — they’re almost a spy,” Trump said.

“I want to know who’s the person, who’s the person who gave the whistleblower the information? Because that’s close to a spy,” he continued. “You know what we used to do in the old days when we were smart? Right? The spies and treason, we used to handle it a little differently than we do now.”

A few attendees laughed at the casually menacing remark, but the ballroom at the Intercontinental Hotel in New York stayed mostly silent.

A person attending the event provided the Los Angeles Times with a recording of the president’s remarks. The event was arranged so the president could thank the U.S. ambassador to the United Nations, Kelly Craft, and her staff as he wound up four days of meetings around the U.N. General Assembly. Trump spoke just as Joseph Maguire, the acting director of national intelligence, was defending the whistleblower at a hearing in the House Intelligence Committee, saying the individual “did the right thing” and followed the law “every step of the way.”

Rep. Adam B. Schiff, D-Calif.,, who heads the committee and led the questioning of Maguire, said later that Trump’s crude comments in New York were intended to intimidate witnesses in the fast-moving impeachment inquiry.

“That kind of incitement to violence is only going to chill other witnesses when they come forward. And that is it’s very intent, to intimidate the witnesses,” Schiff said.

“It’s pretty clear the president is going to make (the inquiry) as difficult as possible, and do so in as dangerous and unethical a way as possible,” he added.

Schiff later issued a formal statement on the matter along with Rep. Eliot L. Engel, chairman of the Foreign Affairs Committee, and Rep. Elijah E. Cummings, chairman of the Oversight Committee, warning the president to end such intimidation efforts.

“President Trump is fully aware that our committees are seeking testimony from this whistleblower and others referenced in the whistleblower’s complaint released today as part of the House’s impeachment inquiry, and our nation’s laws prohibit efforts to discourage, intimidate or otherwise pressure a witness not to provide testimony to Congress,” the statement read in part.

The president has often expressed nostalgia for the raw violence of bygone days, and his rhetoric has been cited by some who have resorted to physical violence.

His remarks Thursday drew harsh criticism from former national security officials, Democratic lawmakers and whistleblower advocates.