President Donald Trump announced that a 25% tariff on imports from Canada and Mexico would take effect Tuesday, citing fentanyl trafficking as justification. He stated there is no room left for negotiations, dashing hopes of avoiding a trade war with two key U.S. trading partners. The S&P 500 dropped over 1%, marking its worst day since December. Canadian Prime Minister Justin Trudeau has vowed retaliatory tariffs on over $150 billion of U.S. goods. Trump also imposed an additional 10% tariff on Chinese imports. Critics warn the tariffs will raise consumer prices, but Trump maintains they strengthen U.S. leverage in global trade.