U.S. President Donald Trump said Friday that Canada has been “ripping off” the United States for years with tariffs on lumber and dairy products and threatened to place reciprocal tariffs on Canada as early as Friday.

Speaking to reporters in the Oval Office, Trump said the “tremendous tariffs” Canada imposes on U.S. dairy and lumber products made it impossible for the U.S. to sell its products in Canada. He said unless Canada agrees to drop them, he would impose the same tariff on Canada.