Trump Threatens Canada With Tariffs Over Wildfire Smoke Blanketing Northern US

President Trump said Friday he’s holding Canada responsible for wildfire smoke that has spread hazardous air across much of the Midwestern and eastern United States, threatening to pile additional costs onto the tariffs Canada already pays.

“We are holding Canada responsible for the fact that they are not properly maintaining their Forests, and Brush therein, and the United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!” Trump wrote on Truth Social, adding that the situation amounted to “Willful Negligence” and that its cost “must of necessity be added to the TARIFFS Canada is currently paying.” He said he planned to call Canadian Prime Minister Mark Carney later Friday to press for action.

The smoke is coming from hundreds of active wildfires, most concentrated in northwestern Ontario, that have triggered evacuations across the province. More than 100 million people across 18 states and Washington, D.C., were under air quality alerts as of Friday, with conditions ranging from “very unhealthy” to “hazardous” in a band stretching from northeastern Minnesota to southeastern Virginia. Detroit ranked as having the worst air quality of any major city in the world on both Thursday and Friday on the IQAir global index, a ranking Toronto had held earlier in the week.

Trump’s comments follow days of similar criticism from other Republican officials. Four Michigan congressional representatives, Jack Bergman, John James, Lisa McClain and John Moolenaar, sent a joint letter this week arguing that Canada hadn’t acted with urgency to address the recurring smoke problem. James, who is also running for Michigan governor with Trump’s endorsement, separately posted what he called a “final warning to Canada,” arguing that American lungs were paying for Canadian inaction. In Ohio, Republican Sen. Bernie Moreno also criticized Carney’s handling of the fires in a social media post.

Canada’s response

Ontario Premier Doug Ford pushed back hours before Trump’s post, telling American politicians to stop “chirping” about the smoke and instead offer help, pointing to Canada’s own assistance during past U.S. natural disasters. Carney, in a post earlier in the week, acknowledged that wildfires had “escalated significantly” in recent weeks, particularly in northwestern Ontario, where thousands of residents have been forced to evacuate.

Broader US-Canada tariff dispute

Canada has been a frequent target of Trump’s tariff policy, with the president previously citing disputes over lumber trade and the U.S. auto industry as justification for some of his steepest tariffs on any single trading partner. Even so, Canada has remained largely shielded by the USMCA trade agreement, which Trump himself renegotiated during his first term.

The tariff threat also comes after the Supreme Court ruled Trump could not use emergency powers to impose tariffs unilaterally, a decision that has pushed the administration toward slower, statute-based processes requiring formal investigations and public comment periods, though officials have said they intend to eventually restore the country’s effective tariff rate to where it stood earlier this year.

It remains unclear what legal mechanism the administration would use to tie new tariffs specifically to wildfire smoke, and the White House had not detailed a formal proposal as of Friday.