"Spies and treason" used to be handled "a little differently than we do now," Donald Trump said

President Donald Trump called his struggle with Democrats threatening impeachment a "war," a video of comments that he expected to remain private showed Friday.

"We're at war. These people are sick," Trump says in the video obtained by Bloomberg.

He was speaking at a closed-doors gathering with US diplomats in New York on Thursday and apparently filmed by one of the people attending.

The event was held in the wake of the Democrats' decision t launch an impeachment investigation into Trump's alleged attempt to arm-twist the Ukrainian president into providing dirt on one of his main 2020 election rivals, Joe Biden.

The recording of the event, part of which was first published by the LA Times, showed Trump suggesting that whoever gave compromising information to the whistleblower was "close to a spy."

He went on to say that "spies and treason" used to be handled "a little differently than we do now."

While that comment prompted chuckles from the crowd, it has since been criticized by Trump's opponents as being a veiled threat to the safety of the whistleblower and his sources.

The extended video clip published by Bloomberg showed more of the remarks in which Trump also refers to Biden as "dumb as a rock" -- getting more laughter from the diplomats.

He also calls journalists "animals," "scum" and "crooked."