LA MALBAIE, Quebec - U.S. President Donald Trump lashed out at Canada and the European Union on Friday, setting the tone for a hostile Group of Seven summit and raising the specter of a trade war that has unnerved Washington's top allies as well as investors.
The confrontation over U.S. tariffs on steel and aluminum imports threatened to rupture the G7, which during its 42-year history has traditionally sought to find consensus on the economy and other issues.
Trump, who aides said has scant interest in multilateralism, resumed his tirade against G7 members and their "unfair trade practices" early on Friday. The White House said he would leave the two-day summit in Canada four hours earlier than originally planned.
The U.S. leader will miss talks about climate change and clean energy, and will have left Canada by the time Canadian Prime Minister Justin Trudeau and other leaders begin closing news conferences likely to be laden with criticism of Washington's trade policy.
"We're going to deal with the unfair trade practices. If you look at what Canada, and Mexico, the European Union - all of them - have been doing to us for many, many decades. We have to change it. And they understand it's going to happen," Trump said before departing for the summit in La Malbaie, Quebec.
"We are going to do very well. Now, if we're unable to make a deal we'll terminate NAFTA, we'll have a better deal," Trump said, adding that the United States would be better off without trade pacts such as the North American Free Trade Agreement.
Canada and Mexico, the other members of NAFTA, have been frustrated by what they see as unacceptable U.S. demands in slow-moving talks to modernize the deal.
Trump also said that Russia should be allowed again to attend G7 summits.
A spokesman for Canada's Trudeau said that Ottawa's position against such a move had not changed.
Officials have conceded the mood at the summit will likely be exceptionally tense.
Although Trump said the tariffs are necessary to protect U.S. industry and workers, Canada and the EU have denounced them as illegal and are preparing retaliation, raising the prospect of a tit-for-tit escalation.
U.S. stock indexes opened lower on Friday partly due to investor nervousness over the G7 summit.
French President Emmanuel Macron warned Trump in a rare rebuke on Thursday that the other six members of the G7 might form their own group, adding that no leader "isforever."
British Prime Minister Theresa May took a more measured tone, telling reporters she wanted the EU to use restraint in retaliation against U.S. tariffs and that the response must be proportionate and legal.
Trump showed no sign of backing down on Friday after accusing both France and Canada of imposing massive tariffs on U.S. goods, and then lashing out at Trudeau for "being so indignant."
The White House subsequently announced the president would leave on Saturday, before the summit formally ends, to fly to Singapore to meet with North Korean leader Kim Jong Un.
While the G7 chiefs have largely praised Trump for his efforts to stabilise the Korean peninsula, they are unhappy he pulled out of an international agreement designed to limit Iran's nuclear ambitions.
In Germany, top officials called for Europe to remain unified in the face of rising trade tensions with the United States even as they maintained that America remained its closest partner outside the continent.