The United States is imposing 50% tariffs on $20 billion worth of Canadian products after last-ditch negotiations failed to resolve the latest strain in relations between the historic allies. Canada says it will retaliate. President Donald Trump’s import taxes are taking effect Saturday and will hit about 5% of what Canada ships to the United States every year. That covers everything from hockey sticks to tongue depressors. Canadian Prime Minister Mark Carney says his country will match the tariffs "dollar for dollar to protect our workers and businesses.” Both sides are blaming the other for the impasse.