Mr. Trump declared tariffs were the most important topic at the G7 summit, blasting ally nations for what he sees as them taking advantage of the U.S. He said other nations have been treating the U.S. like the "piggy back that everybody's robbing".
The Italian prime minister was due to meet the leaders of France, Germany and the UK before the main summit in a session seen as a European "huddle" created to present a united front to President Trump, who has imposed trade tariffs on the EU and disagrees with the bloc over a nuclear deal with Iran.
Trump tweeted Friday he's "looking forward to straightening out unfair trade deals with G7 countries" at the summit, saying the United States would "come out even better" if the deals were not improved.
"The Prime Minister said nothing he hasn't said before - both in public, and in private conversations with the President".
Trump set the tone before leaving Washington on Friday.
"The American President may not mind being isolated", Macron wrote on Twitter, "but neither do we mind signing a six country agreement if need be". We have to change it.
He later said, "It's going to stop, or we'll stop trading with them".
While it was only the Italian prime minister who agreed with Trump, British PM Theresa May recognised the importance of engaging with Russian Federation, but she said the country would have to make changed before readmission could be discussed.More news: Stormy Daniels' lawyer calls Rudy Giuliani an 'absolute pig' over comments
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Depicting the issue as a question of the past, Trump also noted that Moscow "has spent a lot of money" on the region in the past four years.
"Our values and interests are built through multilateralism, including American interests", Macron said in a tweet.
"Our position has not changed (on Russia)", said Adam Austen, spokesman for Canadian Minister of Foreign Affairs Chrystia Freeland.
Macron said he will huddle with the leaders of Britain, Germany and Italy to forge a common approach on how to handle Donald Trump at the Group of Seven summit in Canada. Trump will leave the summit early to attend a summit in Singapore with North Korean leader Kim Jong Un on Tuesday.
Trudeau has made the issue of gender equality a priority for the gathering.
Later in the evening, during a pre-scheduled photo op, Trudeau was asked about Trump's late tweets about the communique and whether the development could have an impact on the future of the G7.
Officials have conceded the mood at the summit will likely be exceptionally tense.
Trump, who repeated that the tariffs are meant to protect USA industry and workers from what he describes as unfair global competition, said he had suggested to the other G7 leaders that all trade barriers, including tariffs and subsidies, be eliminated.