As the leaders of the top industrialised democracies began meeting ahead of the G7 summit in Quebec, European leaders warned that Trump's stance threatens the Western-led world order.
Thursday, Trump took aim at Trudeau and Macron, accusing them of benefiting from one-sided trade arrangements with the United States. "I think it will be very positive", Mr Trump said on Friday, without giving details.
Canada hosts this year's G7 in La Malbaie, Quebec.
Image copyright JESCO DENZE What was agreed?
"President Trump is targeting the dairy sector because he wants to dump US dairy into Canada", Lampron told The Canadian Press, adding that Canada imports five times more dairy from the USA than it exports. In his tweetstorm - and again on Saturday - the President said that such actions were hurting USA farmers and "killing our agriculture".
But Trudeau says what the leaders did this weekend was "roll up our sleeves" and figure out language they could agree to on a broad range of issues.
Merkel is proposing a forum - a "shared evaluation mechanism" - aimed at defusing the tensions with the US The idea has the backing of other European members, though it's unclear if it will get support from the Trump administration.More news: Neymar's return from injury 'better than I expected' - Brazil boss Tite
Trump planned to leave the summit on Saturday before it discussed climate change and the health of oceans, underlining fractures in the G7 exacerbated by the tariffs.
During the call in May, sources told CNN that Trudeau asked Trump how he could justify national security as a reason for placing tariffs on Canadian steel and aluminum.
Trump will be leaving the summit four hours earlier to travel to Singapore to meet North Korean leader Kim Jong-un.
'There will not be a sunset clause. we will not, can not sign a trade deal that expires automatically every five years, ' he told a news conference at the end of a Group of Seven summit in Quebec. "We're like the piggy bank that everybody is robbing".
Media captionDairy wars: Why is Trump threatening Canada over milk? "Tariffs will come way down". Its trade ties with Russian Federation are worth several tens of billions of euros each year, while several leading figures in both the Five Star Movement (M5S) and the League, the two populist parties that make up the coalition government, have expressed personal admiration for President Vladimir Putin. He added that he did not blame G7 leaders for the "unfair" trade deals.
The Group of Seven comprises seven of the largest advanced economies in the world - Canada, France, Germany, Great Britain, Italy, Japan and the United States.
Economics tops the agenda, although the meetings now always branch off to cover major global issues.