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.

Canada faces steep 35% tariffs on almost 60% of its U.S. imports — if President Trump follows through tomorrow on his Aug. 1 deadline for imposing the extraordinary duty.

Canadian Prime Minister Mark Carney voiced disappointment in President Donald Trump’s 35% tariff announcement, but sounded optimistic over exceptions through the U.S.-Mexico-Canada Agreement. Trump announced 35% tariffs on some Canadian goods,