Donald Trump slammed Justin Trudeau as ‘two-faced’ on Wednesday after the Canadian prime minister was caught on camera at Buckingham Palace mocking the president.

‘Well, he’s two-faced,’ Trump said.

Trudeau Emmanuel Macron and Boris Johnson were caught on a hot mic at the Buckingham Palace NATO reception Tuesday evening, appearing to gossip about Trump

The president did not look amused when reporters asked him about the video during his meeting with German chancellor Angela Merkel.

‘And honestly with Trudeau, he’s a nice guy,’ the president added after a long pause.

Trump said Trudeau mocked him because he gave the prime minister grief during their sit down on Tuesday about Canada not paying enough fees to NATO.

‘I find him to be a very nice guy but you know the truth is that I called him out on the fact that he’s not paying 2 per cent and I guess he’s not very happy about it,’ the president said.

‘He’s not paying 2 per cent, and he should be paying 2 per cent. It’s Canada. They have money. And they should be paying 2 per cent. So I called him out on that, and I’m sure he wasn’t happy about that, but that’s the way it is. Look, I’m representing the U.S. And he should be paying more than he’s paying. And he understands it. So I can imagine he’s not that happy. But that’s the way it is,’ he added.

At their Tuesday meeting, Trump noted Canada is ‘slightly delinquent’ in its NATO payments but added: ‘but they’ll be okay. I have confidence.’

‘Some are way below 1 per cent and that’s unacceptable. And then if something happens we’re supposed to protect them and it’s not really fair and it never has been fair and they’re paying up,’ he added.

He and Trudeau then had a back and forth on how much Canada pays the organization.

‘Well, we’ll put them on a payment plan, right?’ Trump said. ‘I’m sure the prime minister would love that. What are you at? What is your number?’

Trudeau added that ‘the number we talked about is 70 per cent increase over these past years including and for the coming years, I think including significant investments in our fighter jets, significant investments in our naval fleets. We are increasing significantly our defense spending from previous governments that cut it.’

But Trump wanted a hard number and asked for it: ‘Where are you now in terms of your number?’

Trudeau said Canada was at 1.4 per cent and ‘continuing to move forward.’

Trump nodded and pointed out ‘they’re getting there. They know it’s important to do that. And their economy is doing well. They’ll get there quickly I think.’

But a clip from the leaders’ reception was the talk of social media late Tuesday night, in which Trudeau was caught mocking the president.

In the clip, British Prime Minister Johnson asks: ‘Is that why you were late?’ as he stoops down and chuckles in disbelief, before Canadian Prime Minister Trudeau, swigging from his drink, shoots back: ‘He was late because he takes a 40 minute press conference off the top.’

The video then cuts to a later clip, which is without context, and sees Macron pointing furiously before Dutch PM Mark Rutte exclaims ‘fake news media’ and Trudeau adds: ‘You just watched his team’s jaws drop to the floor.’  He then motions as if his jaw is dropping. However, it is not known if Trump is the focus of that comment as the video has been edited.

Princess Anne also appears to be involved in the discussion but it is unclear if or how she responds.