Leaders of the G7 nations have papered over the cracks in their alliance at a summit in Canada but came away with little more than an agreement to disagree on trade, as US President Donald Trump defiantly brandished his “America First” agenda.

Trump, who last week slapped tariffs on steel and aluminium imports from Canada, the European Union and Mexico, left the Group of Seven summit early but not before threatening to cut off trade with countries that treated the United States unfairly.

“We’re like the piggy bank that everybody is robbing,” he said at a press conference as his G7 counterparts continued their two-day meeting in La Malbaie, Quebec, and officials hammered out a joint communique.

“This isn’t just G7. I mean, we have India, where some of the tariffs are 100 per cent … And we charge nothing,” Trump said. “And it’s going to stop. Or we’ll stop trading with them.”

In their communique, the leaders of the US, Canada, Britain, France, Italy, Germany and Japan agreed on the need for “free, fair, and mutually beneficial trade” and the importance of fighting protectionism.

“We strive to reduce tariff barriers, non-tariff barriers and subsidies,” they said in the statement.

A member of the French delegation did not mince words, however, briefing reporters about the US president’s closed-door diatribes.

“And so began a long litany of recriminations, somewhat bitter reports that the United States was treated unfairly, that the trading system was totally unfavourable to the United States, the American economy, American workers, the middle class.

“In short, a long, frank rant which is undoubtedly very unusual in this kind of formats.”

Germany’s Angela Merkel and world leaders confronts a stone-faced Donald Trump at the G7 summit.  Photo: Angela Merkel / Instagram

Canadian Prime Minister Justin Trudeau closed the summit by issuing a strong rebuke to Trump’s trade threats, calling them “kind of insulting” and saying they would be met with retaliatory measures from July.

“Canadians are polite and reasonable but we will not be pushed around,” Trudeau told reporters on Saturday.

Trump had told Trudeau any retaliation would be a mistake and the prime minister agreed that it was “not something we want to do”.

Trudeau added that he had not agreed to a new North American Free Trade Agreement with a sunset clause.

Trump, who repeated that his tariffs are meant to protect US industry and workers from unfair international competition, told reporters he had suggested to the other G7 leaders that all trade barriers, including tariffs and subsidies, be eliminated.

He also denied the summit had been contentious, a remark that contradicted what one G7 official described as an “extraordinary” exchange on Friday in which Trump repeated a list of trade grievances, mainly concerning the EU and Canada.

The White House did not immediately respond to requests for comment on the official’s remarks about Trump.

Trump’s counterparts in the G7 have been scrambling this week to try to find some semblance of consensus with Washington on trade and the other key issues that have formed the basis of the 42-year-old organisation.

-AAP