Canadian Prime Minister Justin Trudeau had hoped to visit Washington last week to complete what he thought would be the final stages of the NAFTA renegotiation.
Trudeau said he told Trump directly that Canada 'particularly did not take lightly the fact that [the tariffs were] based on a national security reason'. Manufacturing, an industry Trump focuses on, makes up about 10 percent of USA economic output.
German Chancellor Angela Merkel said earlier that Russia's return to the club was out of the question.
A senior UK Government source yesterday reminded Mr Trump of the reasons for Russia's absence from the G7.
The president said the USA was "pretty close" to reaching an agreement on the North American Free Trade Agreement with Canada and Mexico and had discussed two types of sunset provisions in which any of the countries could leave the deal.
Trump's characterization of the United States' relationships with allies as "a 10" when asked at the news conference about any tensions between his administration and other G7 nations also drew criticism from a senior European diplomat.
Macron said he and Trump held "open and direct" discussions, adding that he thought there was a way to get a "win-win" outcome on trade, though details remained unclear.
And more: "Looking forward to straightening out unfair Trade Deals with the G-7 countries".
Differences over trade tariff disputes and calls to re-admit Russian Federation have overshadowed a summit attended by leaders from from seven of the world's wealthiest nations in Canada.
"The United States will not allow other countries to impose massive Tariffs and Trade Barriers on its farmers, workers and companies", Mr. Trump continued.
President Trump leaves the G-7 summit after holding a press conference in the Canadian resort town of La Malbaie.
"At the same time we will not stop trying to convince our American friends and President Trump that undermining this order makes no sense at all, because it would only play into the hands of those who seek a new post-West order where liberal democracy and fundamental freedoms would cease to exist".
Meanwhile, Trump went after Trudeau in a series of tweets just hours before the summit on Friday.
"We're either going to have NAFTA in a better negotiated form or we're going to have two deals", the USA president said.
Trudeau said he had told Trump that the talks had been made more complicated by a USA decision to impose tariffs on Canadian steel and aluminum, ostensibly for national security reasons.
Just after 6 a.m., Trump used the social media platform to accuse Canada of charging USA customers astronomical tariffs on dairy products.
Leading up to the meetings, Trump, Trudeau and French President Emmanuel Macron had suggested the potential for a tough tone, though they were cordial in face-to-face meetings.