OTTAWA -- OTTAWA - The latest snafu in the relationship between Prime Minister Justin Trudeau and U.S. President Donald Trump played out on the public stage of an international summit on Wednesday. But the leaders of two of the world's closest allies have had their prickly exchanges before.

CHARLEVOIX, 2018

At the closing of a G7 summit, which Canada hosted in Quebec, Trudeau reiterated his criticisms of American tariffs on Canadian steel and aluminum. Tweeting aboard Air Force One on his way home, Trump called the prime minister "very dishonest and weak" and withdrew American support for the joint leaders' statement at the summit conclusion.

"I see the television and he's giving a news conference about how he 'will not be pushed around' by the United States. And I say, 'Push him around? We just shook hands,"' Trump said the day after.

Two senior Trump advisers piled on. Economic adviser Larry Kudlow told CNN Trudeau "stabbed us in the back." Over on Fox News, Peter Navarro, in charge of trade policy, said "there's a special place in hell" for a foreign leader engaging in "bad-faith diplomacy" with Trump.

Chrystia Freeland, then foreign-affairs minister, said the Canadians wouldn't resort to personal attacks in their response.

UN GENERAL ASSEMBLY, 2018

Trump mused about taxing cars crossing into the U.S. from Canada during a press conference on the margins of the UN General Assembly in September, talking about negotiations for a renewed North American free-trade pact.

"We're very unhappy with the negotiations and the negotiating style of Canada. We don't like their representative very much," Trump said, referring to Freeland.

Trump also said he refused a meeting with Trudeau -- a meeting Trudeau office said it had never requested.

All of this followed a leaders' luncheon where Trump only took notice of the prime minister when Trudeau tapped the president on the shoulder, then shook hands with a seated Trump.

Trudeau didn't see what the fuss was about, calling it "an interaction like so many" at the UN -- "quick but cordial."

"There are all sorts of opportunities for me to speak to President Trump," Trudeau demurred, "and that was not the time."

NATO, 2019

Trudeau stood chatting with French President Emmanuel Macron, British Prime Minister Boris Johnson, Prime Minister Mark Rutte of the Netherlands, and Princess Anne at a reception at Buckingham Palace. The host pool cameras focused on the group as they spoke candidly about Trump's lengthy interactions with reporters during bilateral meetings.

"He was late because he takes a 40-minute press conference off the top," Trudeau said at one point. Trudeau was also heard saying Trump's "team's jaws drop(ped) to the floor" when the Trump announced the next G7 summit would be held at Camp David, an idea Trump had previously raised but not formalized.

The next day, Trump told reporters -- during another impromptu news conference before his meeting with German Chancellor Angela Merkel -- that Trudeau is "two-faced," but appeared to brush off what the prime minister said. Trump chalked it all up to his calling out Trudeau for not meeting a defence-spending commitment among NATO members, but noted Trudeau was a "very nice guy."

This report by The Canadian Press was first published Dec. 4, 2019.