US President Donald Trump has said he is immediately ending all trade negotiations with Canada.
In a post on Truth Social, Trump wrote that the country had run an advert featuring former US President Ronald Reagan speaking negatively about tariffs.
"Based on their egregious behavior, ALL TRADE NEGOTIATIONS WITH CANADA ARE HEREBY TERMINATED," Trump wrote late on Thursday.
The US president has imposed a 35% levy on Canadian imports, although he has allowed exemptions for goods that fall under the USMCA - a free trade agreement with Mexico and Canada that Trump negotiated during his first term.
Trump said the video, sponsored by the Ontario government, was designed to "interfere with" the US Supreme Court, referring to an upcoming decision in November on whether Washington's sweeping global tariffs are legal.
The court's decision represents the biggest test of Trump's presidential authority and signature economic policy, potentially forcing the US to refund billions collected in tariffs.
