The American leader said a three-country deal would only be possible with substantial changes, and reiterated his interest instead in forming separate two-way trade accords with Mexico and Canada - an interest Canada has made clear it does not share.
"Ultimately that's what you want".
After Trump's angry tweets, Trudeau's office issued a brief response: "We are focused on everything we accomplished here at the G7 summit". Intelligence officials say the former KGB spymaster has been especially busy making mischief around the globe - including meddling in the 2016 USA elections.
"Canadians, we're polite, we're reasonable but we also will not be pushed around", Trudeau, the host of the two-day summit in La Malbaie, Quebec, told reporters.
"I figured", he said dismissively, when the questioner identified himself as representing CNN.
The US leader had left the meeting early en route for Singapore and a historic nuclear summit with North Korea's Kim Jong Un, only to take exception to comments made by Canada's Prime Minister Justin Trudeau at a news conference back on the ground.
Friday morning he was spitting again: "Canada charges the US a 270% tariff on Dairy Products!"
A few hours earlier, Trudeau had told reporters that all seven leaders had come together to sign the joint declaration. "Angela (Merkel) and Emmanuel (Macron) and Justin (Trudeau) - I would say the relationship is a 10". "Trade", Trump wrote in a pair of tweets. "I blame, as I said, I blame our past leaders for allowing this to happen", he said. "While sending their product into our country tax free".
"They do so much more business with us than we do with them ... the numbers are so astronomically against them? we win that war a thousand times out of a thousand".
The summit came during an ongoing trade dispute with China and served as a precursor to the unprecedented meeting with Kim, in which Trump has sought to extend a hand to the Asian autocrat who has long bedeviled the worldwide order. "With one country we have $375 billion in trade deficits".
Anthony Bourdain's death impacts local community
Mary's Medical Center in Huntington, says signs can be hard to see but if you look closely, you can find some telling signs. That ranked 16 highest in the country , trailing most of the Rocky Mountain west, where rates are highest.
Canadian Prime Minister Justin Trudeau vowed afterwards to press ahead with retaliatory tariffs on 1 July.
"Trade must be not only free but also fair and reciprocal", Navarro said in an op-ed in The New York Times. In 2003, France and Germany broke with the United States in a bitter dispute over the U.S. invasion of Iraq.
An official from French President Emmanuel Macron's office said there was still hope a joint communique would be signed, with Washington opting out of clauses on climate and the environment, but that USA negotiators are opposing language on strengthening global trade oversight.
"Very dishonest and weak" he claimed, adding in a separate tweet: "I have instructed our United States reps not to endorse the communique". "That would be the ultimate thing, whether or not that works, but I did suggest it". But the lead ministers from both countries talked trade on the sidelines of the G7 leaders' meeting on Friday. He said he expressed to Trump "that Canadians did not take it lightly that the United States has moved forward with significant tariffs on our steel and aluminum industry".
Trump himself insisted relationships with allies were a "ten" just before he left the summit.
Trump's apparent threat to end USA trade deals with top allies came as he feuded with French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau and other leaders over the trade war he instigated late last month.
His anger was revealing of his operating method as President, his attitude towards America's traditional foreign policy positions and his skill in using theatrical moments on the world stage to send a strong message to his loyal voters back home. Tariffs have been falling for decades due to free trade agreements.
The leaders of the G7, the world's most powerful industrialized countries including Canada, France, Germany, Italy, Britain, Japan and the United States, meet every year to discuss collaboration on issues like world economy, climate change, security and peace. Tariffs will come way down.
A member of Macron's team characterised the talks as "frank and robust", with Trump first repeating his lengthy diatribe about what he regards as unfair trade restrictions - before the Europeans responded with facts and figures they felt would blunt his argument. We have a tremendous trade imbalance.