Trump's remarks follow his meeting yesterday with Trudeau in which the two men appeared to get along — though Trump needled Trudeau over Canada's defense spending.
The president was reacting to a video that appeared to show the Canadian prime minister and other world leaders discussing Trump, though he is never mentioned by name.
Canada, a NATO member, spends about 1.4% of its gross domestic product on defense. Trump and past U.S. presidents have urged the alliance's members to spend 2% or more on defense. At present, seven of NATO's 29 members have reached that target. The U.S. is by far the largest contributor to the alliance, which was set up during the Cold War to protect Western Europe from Russian and Eastern bloc aggression.