CTV National News for Tuesday, June 23, 2026: U.S. ambassador responds to questions on Canada-U.S. tensions

Montreal mourns victims of the deadly attack as investigators reveal new details and police warn about copycat threats; A Canadian-led study is challenging traditional breast cancer care, finding some patients may benefit from less intensive treatment; U.S. Ambassador Pete Hoekstra discussed Canadians returning to the U.S. and weighed in on relations between Ottawa and Washington.