If they dont back down and Trump does try to stop - or at least slow - the flow of trade, it could impact the flow of hundreds of billions of dollars in goods, potentially impacting millions of jobs in the US and around the world. Both Moscow and Trump have denied the allegations.
Trump said that he also discussed the possibility of Russian rejoining the summit and immigration.
Led by the USA, the group kicked out Russian Federation in 2014 over its annexation of Crimea and its support for pro-Russia separatists in Ukraine.
"Were like the piggy bank that everybody is robbing", Trump said.
But Trump made it sound like other countries acknowledged that they were cheating the U.S.in these trade deals and he had finally caught them in the act.
"Were looking for peace in the world".
Mr Trump is expected to leave the summit early and travel to Singapore ahead of a meeting there with the North Korean leader Kim Jong-un on Tuesday.
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As for the royal pair's plans to start a family, in an interview with BBC Harry revealed they hope to become parents one day. However, it's well known that Her Majesty regularly changes around the photographs in her Audience Room.
Trump says he spoke with world leaders about his trade policies and called for the elimination of tariffs, trade barriers or subsidies.
He said: "Russia should be in this meeting". The U.S. president delivered a rambling statement before taking questions from journalists.
"Trump came late, he's leaving early and he gave no ground whatsoever", Al Jazeera's John Hendren, reporting from Quebec, said.
His statement came after considerable rancor reportedly enveloped the G-7 summit, an annual meeting in which the leaders of the seven most industrialized nations-Canada, France, Germany, Italy, Japan, the United Kingdom and the USA - come together to discuss foreign affairs.
"If they retaliate they are making a mistake because.they do so much more business with us than we do with them that we can't lose that".
Trump's strained relationship with the rest of the G7 was evident on Saturday when he arrived late for the opening session, with Trudeau addressing a gathering that included an empty chair where the president was meant to be.
"We are very clear that Canada does not pose a national security threat to the United States", she said.
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Some of the spotted cars have been wearing exhaust exit surrounds that were fake and fitted to hide the car's identity. The Porsche is expected to have a similar price to the Model S too, somewhere north of $80,000.
A member of Macron's team characterised Friday's talks as "frank and robust", with Trump first repeating his lengthy diatribe about what he regards as unfair trade restrictions - before the Europeans responded with facts and figures they felt would blunt his argument.
In his final news conference before leaving, Mr Trump said trade was at the top of the agenda and the United States has been taken advantage of for decades and it cannot go on.
Trump's abbreviated stay at this Quebec resort saw him continuing the same type of tough talk on trade as when he departed the White House, accusing the summit's host, Canadian Prime Minister Justin Trudeau, of being "indignant".
President Donald Trump has opened his second day at an worldwide summit at a breakfast discussion on gender equality.
In public, Trump bantered easily with his fellow leaders, but the meeting came at a tense moment in the relationships, with allies steaming over Trump's new tariffs on imported steel and aluminum from Canada, Mexico and the European Union. "They know it", he added. He says gender equality must "cut through" everything the G-7 does.
The president went into the meeting under intense pressure from foreign leaders after he slapped high tariffs on steel and aluminum imports, citing US national security needs.
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Until the team news is confirmed, it's hard to get involved here. They joined up late after their Champions League final defeat...