President Trump is terminating trade talks with Canada, saying that its most populous province interfered in the legal fight over his trade agenda with a television ad featuring Ronald Reagan. Mr. Trump, writing on Truth Social, called the ad from Ontario inaccurate and said levies on goods brought into U.S. markets remain vital for national security and the American economy. “Based on their egregious behavior, ALL TRADE NEGOTIATIONS WITH CANADA ARE HEREBY TERMINATED,” Mr. Trump wrote.