The country’s new prime minister, Mark Carney, has been called the “Trump whisperer,” and negotiations have been cordial and professional. But it’s been a wild ride.

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.

Canada faces another set of tariffs in its ongoing trade talks with the U.S. However, in this latest round of tariff announcements, investors have learned to largely tune them out as negotiating bluster rather than policy commitments.

Trump this spring imposed a 25% tariff on cars and car parts, including those from Canada. But certain cars and parts qualify for preferential treatment under the USMCA, meaning the 25% tariff applies only to the non-U.S. content of the automobile or part.

The letter reiterated Trump’s complaints about dairy quotas, fentanyl and the U.S. trade deficit, which is mostly fueled by American refineries’ thirst for Canadian oil. His social media post caused the Canadian dollar to immediately tumble, indicating the market wasn’t expecting this escalation.

Latest news and live updates as Marco Rubio meets with Russian foreign minister amid tensions over Ukraine and Trump releases tariff letters to trading partners.

"America will, once again, build a DOMINANT Copper Industry," Trump said in a post on his Truth Social media platform.