Prime Minister of Canada Justin Trudeau (R) speaks with US President Donald Trump during the G7 summit Leon Neal/Getty Images

Canadian Prime Minister Justin Trudeau was caught on camera appearing to mock President Donald Trump in front of world leaders at a NATO summit reception on Tuesday night.

Trump responded on Wednesday by calling Trudeau „two-faced.“

He also said Trudeau was „not very happy“ about his admonishing Canada for not spending 2% of its gross domestic product on defense.

Later in the day Trump himself was caught on mic saying: „That was funny when I said the guy is two-faced,“ according to White House pool reporters.

The US president was embarrassed by other world leaders on the first day of the NATO summit, suggesting that no one is bothering to take him seriously anymore.

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President Donald Trump called Canadian Prime Minister Justin Trudeau „two-faced“ after Trudeau was caught mocking him behind his back.

In a video published by the Canadian Broadcasting Corporation, Trudeau appeared to make fun of Trump’s 40-minute press conference at the NATO summit on Tuesday.

Trudeau was in conversation with French President Emmanuel Macron, UK Prime Minister Boris Johnson, Dutch Prime Minister Mark Rutte, and Princess Anne.

„He was late because he takes a 40-minute press conference off the top,“ Trudeau said.

„You just watched his team’s jaws drop to the floor,“ he later said.

Johnson and Macron appeared to be laughing during that conversation.

Watch Trudeau’s hot-mic moment:

Tweet Embed:

//twitter.com/mims/statuses/1202008162997538817?ref_src=twsrc%5Etfw

.@JustinTrudeau, @EmmanuelMacron, @BorisJohnson and other VIPs shared a few words at a Buckingham Palace reception Tuesday. No one mentions @realDonaldTrump by name, but they seem to be discussing his lengthy impromptu press conferences from earlier in the day. (Video: Host Pool) pic.twitter.com/dVgj48rpOP

Trudeau did not name Trump, but the context of his comments suggest he was referring to the president.

In response, Trump told reporters on Wednesday that Trudeau was „two-faced.“

„And honestly, with Trudeau, he’s a nice guy — I find him to be a very nice guy — but you know, the truth is that I called him out on the fact he’s not paying 2%, and I guess he’s not very happy about it,“ he said, referring to his urging Canada to spend 2% of its gross domestic product on defense.

„It’s Canada, they have money, and they should be paying 2%,“ Trump said. „So I called him out on that, and I’m sure he wasn’t happy about it, but that’s the way it is.“

Trump has long railed against what he perceives as the US’s outsized contribution to NATO’s defense budget. NATO last week announced it would reduce the US’s share and increase Germany’s, and Trump claimed credit for it.

„Look, I’m representing the US, and he should be paying more than he’s paying, and he understands that,“ Trump said on Wednesday. „So I can imagine he’s not that happy, but that’s the way it is,“ he added.

U.S. President Donald Trump, center left, and Canadian Prime Minister Justin Trudeau arrive for a round table meeting during a NATO leaders meeting at The Grove hotel and resort in Watford, Hertfordshire, England, Wednesday, Dec. 4, 2019. As NATO leaders meet and show that the world’s biggest security alliance is adapting to modern threats, NATO Secretary-General Jens Stoltenberg is refusing to concede that the future of the 29-member alliance is under a cloud. (AP Photo/Evan Vucci) Associated Press

Later on Wednesday Trump was caught in his own hot-mic moment, saying: „That was funny when I said the guy is two-faced,“ referring to his comments on Trudeau, according to multiple White House pool reporters.

Trudeau on Wednesday confirmed that he was talking about Trump’s Tuesday morning press conference, and that his reference to US aides‘ jaws dropping was on his announcement that the next G7 summit would take place in Camp David.

Johnson has denied laughing at Trump at the time, telling journalists that reports of the world leaders laughing at Trump was „complete nonsense, I don’t know where that’s from.“

Trump’s clout on the world stage was severely undermined at the NATO summit as Trudeau appeared to mock him, Macron publicly fact-checked his claims about ISIS, and Johnson distanced himself from Trump for fear that he would jeopardize his chance in the UK general election this month.