President Donald Trump said the US will put a 35% tariff on some imports from Canada, escalating the tensions between two countries that have impaired one of the world’s largest trading relationships.

Trump’s promise to impose 30% tariffs on imports from Mexico and 35% on imports from Canada beginning tomorrow could hammer up to three-fourths of their U.S. imports.

The imbalance in President Trump’s treatment of America’s closest trading partners may come from his desire to make Canada the 51st state, some Canadians believe.