President Donald Trump late Thursday threatened a 35% tariff on goods imported from Canada, a dramatic escalation in an on-again, off-again trade war with America’s northern neighbor and one of its most important trading partners.

Trump wrote to Carney to inform him that, from August 1, Canada will face a 35 percent import tariff after the two sides failed to reach a deal during the recent pause. The American leader said he would consider revising the 35 percent tariff "if Canada works with me to stop the flow of Fentanyl".