Trump's comments have the potential to further upend talks with other leaders. US intelligence officials believe Russia interfered in the 2016 election, and part of this year's G7 summit was supposed to focus on protecting democracies from foreign meddling. Trump has sought to improve relations between the United States and Russia since taking office. The US government and other nations have imposed strict sanctions on Russia related to its involvement in Crimea, and those penalties remain in effect. Trump on Friday reiterated his plans to take a tough stance on trade with US allies at the summit, threatening again to withdraw from the North American Free Trade Agreement. Loading Replay Replay video Play video Play video "We're going to deal with the unfair trade practices... We have to change it, and they understand it's going to happen," Trump said. "If we're unable to make a deal, we'll terminate NAFTA. We'll make a better deal."

In an earlier Twitter post, Trump said the United States would emerge victorious if other nations refused to accede to his trade demands, suggesting he plans to employ a take-it-or-leave-it bargaining position with other world leaders at the Group of Seven summit here. "Looking forward to straightening out unfair Trade Deals with the G-7 countries," Trump wrote. "If it doesn't happen, we come out even better!" Loading On Thursday evening, when tensions between Trump, French President Emmanuel Macron, and Canadian Prime Minister Justin Trudeau appeared to be boiling over, the US leader vowed to impose new tariffs and other economic penalties against Canada and the US if they didn't allow more American imports into their countries. "Take down your tariffs & barriers or we will more than match you!" he wrote on Twitter. He didn't specify what products he could seek to target.

Trump effectively upended the two-day G7 summit even before it began by raising the prospect of refusing to sign on to a joint statement with other leaders asserting commonly shared principles and values. Macron, Trudeau and other world leaders spent much of 2017 tiptoeing around the US President, aware of his "America First" agenda but hoping to draw him closer to multinational organisations they believe can best address global issues. But in recent weeks there are signs world leaders have scrapped that approach and now plan to deal with Trump in a more adversarial way, particularly after the White House announced it would begin imposing tariffs on steel and aluminium imports from US allies beginning in June. Macron on Thursday said Trump was isolating the United States and suggested foreign leaders might simply wait until Trump's time in the White House has concluded before re-engaging with the United States. Trump, meanwhile, said Trudeau was acting "indignant" and attacked the US' northern neighbour in a series of Twitter posts, focusing in part on Canadian dairy policy.

Trump is now engaged in a series of trade wars with numerous countries in Europe, North America, and Asia, which could impact the flow of hundreds of billions of dollars in goods, including automobiles, agricultural products, and technology. He wants Europe and Japan to lower tariffs on imports of automobiles. He wants China to buy more agriculture and energy products from the United States. He is pushing Mexican leaders for a range of changes to the North American Free Trade Agreement, and he wants that entire pact to expire after five years. Loading His view is that other countries have imposed unfair tariffs limiting US imports for decades but the United States has unwittingly allowed those countries to bring low-cost goods into the United States, hurting US companies and American workers. Foreign leaders are aware of the shaky ground Trump is on when he levels these trade threats, as a growing number of congressional Republicans have expressed outrage and some are trying to intervene to strip his powers away. So far, Trump has held these politicians, including Senator Bob Corker, at bay, but US business groups - worried about the prospect of higher costs driven by Trump's trade threats - are pushing Congress to act.

Trump is scheduled to meet with Macron and Trudeau on Friday, and then he will leave the G-7 summit early on Saturday, an unexpected schedule change that will pull him out of discussions on climate change. The Washington Post