Trump has justified tariffs on goods from Canada, the top U.S. export market, by accusing it of failing to stop the cross-border flow of fentanyl, even though U.S. government data shows Canada accounts for only 1% of the fentanyl that enters the United States.

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.

The Canadian team working on a trade deal with the United States could walk away from talks in the wake of a U.S. decision to impose a 35% tariff on some goods from Canada, an adviser to Prime Minister Mark Carney said on Friday.