Donald Trump has called Prime Minister Trudeau "two-faced" after video has surfaced showing the Canadian PM talking a bit of trash with some fellow international leaders.

Trudeau, U.K. PM Boris Johnson, Princess Anne, French president Emmanuel Macron and Dutch PM Mark Rutte were caught on film engaging in a conversation about Trump's press etiquette last night.

Watch Trump call Trudeau 'two-faced' after after PM's candid comments caught on camera. https://t.co/XWr7lxkKdv pic.twitter.com/BhBEowsqtk

— CBC News (@CBCNews) December 4, 2019

"He was late because he takes a 40-minute press conference off the top," Trudeau tells the group. "You just watched his team’s jaws drop to the floor."

Some parts of the chat are indecipherable and there is no direct mention of the U.S. president, but it is understood that he was the source of complaint.

.@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

— Power & Politics (@PnPCBC) December 3, 2019

The conversation took place in Buckingham Palace, at a reception for NATO leaders before the alliance's 70th anniversary summit in London.

When later asked by press if he'd seen the video, Trump said that Trudeau is "a nice guy," but that "he's two-faced."

The US's oldest allies mocking Trump. What does this say about the US's standing in the world? What does this say about our once most steadfast alliances? It goes beyond "gossip worthy." Every US citizen should see first hand what the world thinks of Trump, and this shows it.

— Phillip Olsson (@phillip_olsson) December 4, 2019

He seems to think that Trudeau's remarks in the private conversation were due to the fact that Trump called Canada "slightly delinquent" for not spending two per cent of GDP on defence, in line with a five-year-old NATO agreement for all allied countries to do so by 2024.

The U.S. president cancelled a post-NATO press conference and departed the summit early after the whole incident, tweeting "we won't be doing a press conference at the close of NATO because we did so many over the last two days."

Trump was asked if he saw the video of Trudeau and other world leaders speaking at Buckingham Palace. Of that he says Trudeau is two-faced. Says he called Trudeau out on not spending enough on defence, says he thinks Trudeau was upset about that.

— Katie Simpson (@CBCKatie) December 4, 2019

The two have had quite the rocky relationship, between aggressive and well-practiced handshakes as shows of dominance, trade disputes, Twitter insults and some apparent historical angsts. 

But as the summit video indicates (and as we all knew anyway), Trump doesn't really seem to be on good terms with many world leaders at this point.