Under plans agreed by the UK, US, France, Germany, Canada, Italy and Japan, there will be greater co-ordination to respond to threats including cyber attacks and other breaches of global rules. At the time, he mentioned he was open to renegotiating the pact, but other members expressed resistance to that idea.
Trump will meet with Macron and Trudeau face-to-face on Friday. European Commission President Jean-Claude Juncker offered to visit Washington for an assessment of EU-US trade to help resolve the dispute, an official said.
She said Canada, however, will not change its mind about the USA steel and aluminum tariffs which she termed "illegal". Mr. Conte leads a peculiarly pro-Russia coalition of the populist Five Star Movement and the far-right Lega, whose leader Matteo Salvini signed a co-operation agreement a year ago with Mr. Putin's ruling United Russia party.
On Friday Canada's foreign minister called Mr Trump's tariffs "illegal and absolutely unjustified".
In Trump's first public remarks on Canadian soil, he once again reiterated his desire for separate trade deals with Canada and Mexico, instead of the North American Free Trade Agreement.
Apart from this nascent trade war, Trump has also pulled the US out of the Iran nuclear deal, threatening foreign companies that still want to do business there. And he emphasized a "good relationship" with French President Emmanuel Macron, saying they sometimes have a "little test" on trade, but predicting a positive outcome. "Maybe we should come up with a new slogan", he said.
Trump was the last G7 leader to arrive and will probably be the first to leave on Saturday when he sets off for his nuclear summit with North Korea's Kim Jong Un in Singapore. Trump said at the White House before departing for the Charlevoix region.
Conte's populist coalition includes the right-wing League party which says sanctions on Russian Federation over Ukraine hurt Italian exports.
But Mr Trump predicted the G7 countries would agree on a joint statement after holding talks with Canadian Prime Minister Justin Trudeau. "It could be with Canada, with Mexico, one-on-one", the president added.
Russia was ousted from the elite group in 2014 as punishment for Vladimir Putin's annexation of Crimea, and its support for pro-Russian separatists in Ukraine. Three days after taking office, Trump formally withdrew the USA from another such landmark deal, the Trans-Pacific Partnership, which the Obama administration negotiated with 11 Pacific rim nations.
Trump imposed the tariffs on the grounds that weak domestic industries could affect USA national security.
At one point, Macron waxed on about the apparent negative effect of US hegemony, and suggested nothing short of sheer human mortality and the sweep of history would undo Trump's decision to dump the climate accord that was struck in the French capital nearly three years ago.