"He did a great disservice to the whole G7".
"So we are either going to have NAFTA in a better negotiated form or we're going to have two deals".
"He must mean there are 10 things on which we totally disagree". We are actually working on cutting tariffs and making it all very fair for both countries.
USA trade advisor Peter Navarro, speaking on "Fox News Sunday", reinforced that message.
Just minutes after a joint communique that had been approved by the other leaders of the Group of Seven allies was published, Trump launched a Twitter broadside from aboard Air Force One. Expert observers have said that Justin Trudeau's government would abandon the treaty altogether before sacrificing supply management.
Trump did not specify which of Trudeau's statements he considered false.
Trump's early departure for Singapore, where he meets North Korean leader Kim Jong Un next week, showed his disdain for summit's Saturday afternoon discussion of climate change.
Trump - who has a history of hair-trigger responses to slights - landed in Singapore on Sunday for the Tuesday summit meeting with Kim.
Trump had entered the summit amid a spat with Trudeau and French President Emmanuel Macron over USA tariffs on steel and aluminum.
Trudeau had told reporters that Trump's decision to invoke national security to justify United States tariffs on steel and aluminum imports was "kind of insulting" to Canadian veterans who had stood by their U.S. allies in conflicts dating back to World War I.
Merkel and Trump: A study in contrasting images from G-7
The U.S. has recently thrown up or reinforced several barriers to that open border - in aerospace, lumber, and most recently steel and aluminum.
He added: "Prime Minister Trudeau is being so indignant, bringing up the relationship that the USA and Canada had over the many years and all sorts of other things...but he doesn't bring up the fact that they charge us up to 300% on dairy - hurting our Farmers, killing our Agriculture!"
A few minutes later, Trump changed his Twitter profile header picture from the G7 family photo to a photograph of himself singing the anthem with members of U.S. military in Atlanta in January this year - apparently another jab at his summit-mates, considering how far back he had to dig to find that one.
Trump has also met with President Emmanuel Macron of France to discuss the tariffs.
Trudeau and the other G7 leaders used their meeting to try to persuade Trump to abandon the tariffs, which affect all of America's G7 allies.
French President Emmanuel Macron's office reacted Sunday by saying that "international cooperation can not be dictated by fits of anger and throwaway remarks".
SPD leader Andrea Nahles accused Trump of turning the G7 summit into a disaster with his tweets and bowing out of his global responsibilities.
Over the course of his presidency, Trump has inflamed allies with his isolationist policies, including withdrawing the US from the Paris climate accord and the global Iran nuclear agreement.
In a statement, The Associated Press reported, a spokesman for Trudeau did not address Trump's tweeted insults.
The remarks, following a two-day meeting in Canada with the world's largest industrialized economies, were among the most strident Trump has used to describe what he sees as an out-of-whack global trade system that he says harms US industries.
"No tariffs, no barriers, that's the way it should be, and no subsidies", he said, warning that other countries could lose access to the United States if they don't reduce trade barriers.
Trump had already roiled G-7 members ahead of the summit and raised fears of a trade war when he placed tariffs on steel and aluminum from Canada, the European Union and Mexico.