US President Donald Trump on Wednesday said a 25 percent tariff imposed on cars imported from Canada to the United States could go up.

"When I put tariffs on Canada - they're paying 25 percent - but that could go up, in terms of cars," Trump told reporters in the Oval Office. "All we're doing is we're saying, 'We don't want your cars, in all due respect. We want, really, to make our own cars."