"The idea that we are somehow a national security threat to the United States is quite frankly insulting and unacceptable", Trudeau told NBC last week.
"Justin has agreed to cut all tariffs, all trade barriers", he announced in jest as Trudeau grinned nearby.
The French President has been desperately trying to recruit the German Chancellor as he seeks support for his proposed reforms - a separate Eurozone budget, a Europe-wide finance minister and a new bailout fund - as he hopes to replicate the International Monetary Fund and create a European Monetary Fund. "And that's the key point", Trump said.
Despite the president describing his relationship with the other leaders as "a 10", conversations between the world's largest industrialized countries were thought to be intense as the allies faced off with Trump over tariffs his administration has imposed on them.
But for Trump, infuriating allies with fake facts is just another day at the office.
He will arrive at the annual gathering, held this year in Quebec, but will leave on Saturday morning before the event is over, heading to Singapore for his highly anticipated summit with North Korean leader Kim Jong Un. France's President Emmanuel Macron also put a fearless face on the encounter.
And Trump has done little to ease their jitters.
Paris also delivered a withering response to the USA president's tweeted instruction for American officials to withhold their endorsement.
Though other leaders had their own images of the meeting tweeted out, Denzel's photograph - which shows Merkel standing dominantly over a petulant-looking Trump - became the most enduring after it caught the imagination of the web. In one photo, Xi and Russia's Vladimir Putin, with smiles on their faces, lead other world leaders to stride into a dining hall. Few expect the assembled leaders will even agree on language for a joint "communique" that typically concludes the summit. Trump then declared on Twitter that he no longer endorsed the statement. But the group retreated quickly behind closed doors for the start of their talks.
The French President also condemned Trump over the 2015 Iran nuclear deal, saying that while it was the choice of the USA to participate in the deal, the U.S. should not prevent other nations from dealing with it. Kudlow was vague on whether the summit will produce a joint decision or a clear outcome on trade or other issues, saying "let them meet first". Emmanuel has been very helpful in that regard. "And they understand it's going to happen", Trump said before departing for the summit in La Malbaie, Quebec.
Mr Trump's bombshell announcement that he was backing out of the G-7 communique torpedoed what appeared to be a fragile consensus on the trade dispute between Washington and its top allies.
When Trump met with Macron in France previous year, the two shared an intense handshake that saw both men clench their fists until their knuckles turn white.