President Donald Trump said the U.S. will impose a 35% tariff on all Canadian goods from Aug. 1 and threatened a blanket 15 to 20% levy on most other nations.

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.

President Trump fired off another round of tariff letters to eight countries Wednesday, giving notice that the US will ramp up levies on their exports if they don’t reach a trade deal with Washington by Aug.

"As you will recall, the United States imposed tariffs on Canada to deal with our Nation's Fentanyl crisis, which is caused, in part, by Canada's failure to stop the drugs from pouring into our Country," Trump wrote in a letter to Carney, which was posted on social media late Thursday.

President Donald Trump on Wednesday informed seven more nations about new tariffs, singling out Brazil with a 50% duty because of what he called the "disgrace" of how former President Jair Bolsonaro has been treated and an "unfair trade relationship.

Trump announced a new 35% tariff on Canadian imports starting August 1st, escalating tensions after Ottawa retaliated against earlier U.S. duties, according to CNBC. In a letter to Canadian Prime Minister Mark Carney,

Trump's moves have raised fears that economic growth would slow to a trickle, if not make the U.S. and other nations more vulnerable to a recession.