"Canadians, we're polite, we're reasonable, but we also will not be pushed around," Trudeau said at a news conference.
"I highlighted directly to the president that Canadians did not take it lightly that the United States has moved forward with significant tariffs on our steel and aluminum industry," Trudeau said at a news conference at the meeting's end.
"Particularly, [they] did not take lightly that it's for a national security reason that for Canadians . . . who stood shoulder to shoulder with American soldiers in far off lands in conflicts from the first World War onwards, it's kind of insulting."
At a summit aimed at renewing ties between members after months of trade threats, Trump heightened tensions with allies while reaching out to absent U.S. adversaries.
Trump, as he departed for the G7 summit, called for Russia to be readmitted after it was expelled in 2014 for annexing Ukraine's Crimea. He closed his summit with the treat threats before departing the summit early - skipping a discussion of global climate change - to fly to Singapore for a nuclear summit with North Korean dictator Kim Jong Un.
Now, Trump and foreign leaders face a string of trade decisions that will either preserve the existing global economic system or reshape it, with millions of jobs and trillions of dollars hanging in the balance.
Trump cautioned other nations -those in the G7 and around the world - that the size of the US economy means other nations can't win a trade war. "We win that war a thousand times out of a thousand," Trump said.
And though Trump described foreign leaders as receptive to his demands in private, Trudeau and others showed few, if any, public signs of caving.
German Chancellor Angela Merkel's office released a photo of multiple leaders appearing to confront a displeased Trump. A Reuters photographer, meanwhile, captured a photograph of the imprint that French President Emmanuel Macron left on Trump's right hand after a handshake, suggesting the French leader used a forceful grip.
It was part of a broader approach by foreign leaders to the second G7 meeting of Trump's presidency.
Representatives from other G7 countries said they felt as though they had made progress in conveying their positions to Trump, something many of them felt pressured to do by voters at home.
Despite the tension, the member states' leaders were cordial in person, Trump included. He made first-name references to "Angela" and "Justin," and he repeatedly insisted he blamed previous US leaders, not foreign ones, for what he sees as the global trade imbalance.
Trump said the leaders discussed the question of Russia's inclusion in the group but reached no conclusion. "We didn't do votes or anything, but it has been discussed," he said.
Russia is a permanent member of the UN Security Council and plays a significant role in international security issues. It also holds a seat in the larger Group of 20.
"We're looking for peace in the world. We're not looking to play games," Trump added.
Trump is not the first politician to make the realpolitik argument that Russia belongs at the G7 table, but his position is a complete turnabout from the Obama Administration, which condemned the 2014 annexation and imposed sanctions on Russia as punishment.
"Crimea was let go during the Obama Administration, and, you know, Obama can say all he wants, but he allowed Russia to take Crimea. I might have had a very different" response, Trump said.
Leaders from Canada and the UK rejected Trump's call to bring Russia back, saying Russian President Vladimir Putin would have to make major changes to be welcomed back. Though new Italian Prime Minister Guiseppe Conte sided with Trump.
US intelligence agencies have said they have "high confidence" that Russia interfered in the 2016 election, and part of this year's G7 summit was supposed to focus on protecting democracies from foreign meddling. Special Counsel Robert Mueller is investigating Russian interference efforts, including whether Trump's campaign colluded in any way with Russian officials.
G7 members met in part to discuss how to prevent election interference, and many remain angry over Putin's actions in the Ukraine.
At his news conference, Trump first referred to the Crimean annexation only obliquely.
"Something happened awhile ago where Russia is no longer in," he said. "I think it would be good to have Russia back in."
As they departed it became clear that many are still searching for ways to deal with the unpredictable US leader.
Yesterday NZT, the White House issued a statement saying Trump and Canadian Prime Minister Justin Trudeau were very close to a deal to rework the North American Free Trade Agreement.
But during his comments today, Trump raised multiple options for Nafta, including a potential new deal or the possibility of doing separate deals with Mexico and Canada, effectively cleaving the longtime agreement in two.
"It was not contentious," Trump said. "What was strong was the language that this cannot go on, but the relationships are very good."
"The European Union is brutal to the United States, and they know it," Trump said, adding that other leaders acknowledge as much in private.
"It's like the gig is up," he said. "They can't believe they got away with it."
European officials described things much differently.
Their leaders confronted Trump about how his protectionist policies had given them no choice but to retaliate with tariffs of their own, a person familiar with the encounter said.
These tariffs, they told Trump, would hurt everyone. Trump had tried to essentially splinter the European leaders by negotiating some changes with Germany and different ones with France, but those leaders appeared locked together.
They had been careful not to reveal their approach before meeting with Trump, although it appeared very calculated.
"If you have a strategy, do not explain your strategy before the meeting - because if you are explaining your strategy before the meeting, you are losing your strategy," European Commission President Jean-Claude Juncker told reporters.
As for Trump's proposal to eliminate all tariffs, he said it was unclear how other countries would respond.
"I did suggest it," Trump said. "I guess they are going to go back to the drawing board and check it out."