Washington (CNN) President Donald Trump said Thursday that whoever provided the whistleblower with information about his call with the Ukrainian President is "close to a spy," adding that in the old days spies were dealt with differently.

The comments, first reported by The New York Times, were made to an audience of career foreign service officers who work at the United Nations, two sources who were in the room and one person who knew someone in the room said. One source said the remarks were "shocking" and "eerie."

Other top US government officials were in the room as well, including the new US Ambassador to the UN Kelly Craft.

Not everyone in the room opposed Trump's comments. US Mission to the United Nations employees could invite their friends or family to the event and most of the people who accepted such an invite were Trump supporters who were not startled by Trump's threatening tone, another source said.

Earlier Thursday, a stunning whistleblower complaint alleged Trump abused his official powers "to solicit interference" from Ukraine in the upcoming 2020 election, and the White House took steps to cover it up. Acting Director of National Intelligence Joseph Maguire also testified before the House Intelligence Committee about the whistleblower complaint.

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