Canadian Prime Minister Justin Trudeau said Friday that U.S. President Donald Trump incited an assault on democracy by violent rioters, in a rare case of direct criticism by a political leader to another.

Trudeau described the assault on Capitol Hill as "shocking, deeply disturbing and frankly saddening" and suggested "the losing side gracefully concedes." He had been careful about making remarks on Trump as the U.S. is Canada's largest trading partner.