In a bid to rebuild America's industry, Trump has imposed hefty tariffs on steel and aluminum imports, including those from key G7 allies like Canada, Japan and the European Union. Mexico slapped a 25% import tariff on US steel products, as well as 20% on pork products, 25% on bourbon and duties on other agricultural goods including cranberries.
The EU and Canada have taken steps to retaliate.
While both Macron and Trudeau have forged cordial relationships with Trump, they made it clear they would not be intimidated by the U.S. leader especially in the face of United States tariffs on steel and aluminum imports from Canada, Europe, Japan and Mexico.
Image copyright JESCO DENZE What was agreed?
On Saturday, Mr. Trump arrived late for the first working session on gender equality but Canadian Prime Minister Justin Trudeau forged ahead with opening remarks without him, commenting wryly about "stragglers". "When we can underscore this, and we see that there's a lot of pressure within the USA, perhaps he will revise his position".
Trump fired back soon after on Twitter, addressing both leaders directly, saying they were charging "massive tariffs" on USA goods and had erected other trade barriers.
But even though he has made his criticism of globalization a major part of his appeal to voters, Trump was the main target of a protest by around 400 demonstrators on Thursday night who set fire to United States and other G7 flags.
Trump repeated his call for Russian Federation to be allowed back into the alliance of world powers.
President Trump earlier told reporters he had proposed the idea of a tariff-free G7 to other leaders and described his talks with them as "extremely productive".More news: Floyd "Money" Mayweather again tops Forbes list
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"We're the piggy bank that everybody is robbing".
He rebuked Canadian Prime Minister Justin Trudeau for being "dishonest & weak" and making "false statements".
Trump is heading to Singapore, where he is scheduled to meet on Monday with North Korean leader Kim Jong Un. Trudeau had announced on June 1 that Toronto will levy tariffs on USA products worth about $13 billion (approximately Rs 87,426 crore) from next month.
He said the USA required fair access to markets and an end to unfair trade practices, telling reporters the "United States has been taken advantage of for decades and decades". When questioned on his attack by another reporter Trump defended his practice of attacking the media.
"We will continue to demonstrate that we're interested in defending Canadian interests and, on top of that, it turns out I'm defending American interests because these tariffs they're putting forward are going to hurt American workers as well", Trudeau said Thursday.
The pair have been at odds over whether a sunset clause would be included into any renegotiated trade agreement covering the US, Canada and Mexico, with Mr Trudeau insisting no sunset clause would be included and Mr Trump saying hours earlier that negotiators were "pretty close on the sunset provision".
The US president will come face-to-face at the gathering with world leaders whose views do not chime with his on a range of issues from trade to the environment as well as Iran and the construction of a new US embassy in Jerusalem.
German Chancellor Angela Merkel has predicted the talks at the G-7 on Friday and Saturday will be heated because of the American stance on trade.
Economics tops the agenda, although the meetings now always branch off to cover major global issues.