US President Donald Trump (L) and Turkey's President Recep Tayyip Erdogan (R) pose for the family photo at the NATO summit at the Grove hotel in Watford, northeast of London on December 4, 2019.

Hours before the news conference was set to start, video emerged of Canadian Prime Minister Justin Trudeau caught on a hot mic mocking Trump .

The presser was scheduled to come after a series of bilateral meetings with NATO members, including German Chancellor Angela Merkel and Italian Prime Minister Giuseppe Conte.

"We won't be doing a press conference at the close of NATO because we did so many over the past two days. Safe travels to all!" Trump said.

"When today's meetings are over, I will be heading back to Washington," Trump said in a series of tweets.

President Donald Trump on Wednesday abruptly canceled a press conference that was scheduled to cap a contentious trip to the U.K. for the North Atlantic Treaty Organization's 70th anniversary meeting.

Trump offered a blunt retort when asked Wednesday about Trudeau's comments.

"He's two-faced," Trump said, before adding, "I find him to be a very nice guy but the truth is I called him out on the fact that he's not paying 2% and I guess he's not very happy about it." Trump has long griped about NATO members paying less than their "fair share" toward the alliance, and brought up the issue repeatedly over the two-day anniversary meeting this week.

In an audio clip later published by reporters covering the NATO event, Trump appeared to compliment himself for his harsh words toward Trudeau. "That was funny when I said the guy's two-faced," Trump is heard saying.

Trudeau, speaking with French President Emmanuel Macron, U.K. Prime Minister Boris Johnson and Dutch Prime Minister Mark Rutte, said that Trump "was late because he takes a 40-minute press conference off the top."

"You just watched his team's jaws drop to the floor," Trudeau said at another point in the video, raising his eyebrows and motioning with his hand for effect.

None of the politicians in the hot mic video, which emerged on social media Tuesday evening, mentioned Trump by name. But Trudeau reportedly said Wednesday that it was Trump's surprise announcement of the location for next year's Group of Seven summit that made "his team's jaws drop to the floor."

Trump revealed Tuesday that the 2020 G-7 summit will be held at Camp David in Maryland, weeks after he retreated from a plan to host it at his own Miami golf resort.

Later Wednesday, while sitting alongside Conte, Trump explained that "There's no reason to have press conferences because you had about eight of them," apparently referring to his lengthy prior remarks to reporters.

The hot mic gossip was the latest point of tension at the meeting, but it was far from the only dispute between leaders on display.

Macron defended his recent claim that NATO was suffering from "brain death" from critics including Trump, who had called that comment "very nasty."

The French leader also called out Turkish President Recep Tayyip Erdogan for his threat to oppose NATO's plan for the defense of Baltic countries if it does not recognize groups Turkey deems as terrorists. The White House announced Wednesday morning that Trump had met with Erdogan during the NATO event.