Canada imposed tariffs on about $20 billion worth of U.S. goods on Tuesday, responding to the latest U.S. tariffs.

Prime Minister Mark Carney said U.S. demands could hollow out key Canadian industries and limit the country’s independence.

The dispute is being watched globally as a test of whether a smaller U.S. ally can withstand President Donald Trump’s economic pressure.

The Canadian tariffs cover hundreds of American products, including steel, aluminum, cheese, appliances, clothing, cosmetics and farm equipment.

Rates are set at 15%, 25% or 50%.

Canada says the measures match Washington’s tariffs dollar for dollar and rate for rate.

They cover roughly 6% of the $333.6 billion the United States exported to Canada last year.

Trump has threatened further action, including a ban on Bombardier aircraft sales unless the company builds planes in the U.S.

He has also warned of 50% tariffs on Canadian vehicles, auto parts and steel next year.

Canadian officials say such a move could hammer plants and raise vehicle prices across North America, as parts cross the border repeatedly during production.

Trump’s pressure has backfired in Canada, rallying public support behind Carney.

Canadians have cut travel to the U.S. and boycotted American goods.

Experts say the relationship will not return to its pre-Trump state.

Industry Minister Mélanie Joly said, “I’m convinced that we will be able to show the world that Canada will win this trade war.”