President Donald Trump delivered a threat to foreign leaders during a press conference Saturday at the 2018 G7 summit in Quebec, Canada: If they don't dramatically reduce tariffs and trade barriers, "we'll stop trading with them".
Trump appeared to have taken notice and pushed back: "Please tell Prime Minister Trudeau and President Macron that they are charging the USA massive tariffs and create non-monetary barriers", Trump said in a tweet.
Trump said, referencing the Canadian tariff levied on USA and foreign milk imports.
Trump had told Trudeau any retaliation would be a mistake and the prime minister agreed that it was "not something we want to do".
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".
It is an annual summit bringing together Canada, the United States, the UK, France, Italy, Japan and Germany, which represent more than 60% of global net worth between them.
"They do so much more business with us than we do with them. the numbers are so astronomically against them. we win that war a thousand times out of a thousand".
In a phone call with Mr Trump, he was said to be even more blunt.
"I said very simply that it is not something we are even remotely interested or looking at this time to have Russian Federation returned to the G7", Trudeau said at the press conference following the two-day summit. And we charge nothing", he said.
The G-7 became the G-8 in 1997, when Russian Federation became a member along with Britain, Germany, Italy, Canada, the United States, France and Japan.
"No tariffs, no barriers, that's the way it should be and no subsidies".
Trump, who has exchanged barbs with Macron via Twitter in the lead-up to the summit in Canada, also had warm words for the French president.
"The president will continue to say what he says".
French President Emmanuel Macron said the agreement would be a good first step and represented the G7 nations' desire to stabilize the situation.
Macron said he and Trump held "open and direct" discussions, adding that he thought there was a way to get a "win-win" outcome on trade.
He said he didn't blame the other world leaders, saying their countries struck good deals at America's expense, and said he blamed previous USA presidents.
Mr. Trump's tweets taking aim at the leader of a country that has always been a U.S. ally came after the President left the G7 summit in Canada to travel to Singapore ahead of a planned diplomatic meeting with North Korean Leader Kim Jong-un, CNN reported.
Led by the U.S., the group kicked out Russian Federation in 2014 over its annexation of Crimea and its support for pro-Russia separatists in Ukraine.
On Friday, Mr Trump made a surprise call for Moscow to be readmitted, but German Chancellor Angela Merkel said other members were against the idea.
This year's G7 summit had been dubbed "G6-plus-1" by many, referring to United States isolation over issues including trade and the Iran nuclear deal.