Trump threatens Canada with new tariffs over wildfire smoke as air quality alerts cover 18 US states

Trump's tariff threat

President Donald Trump on Friday threatened to impose additional tariffs on Canada, saying the cost of wildfire smoke drifting across the border is "incalculable" and must be added to existing levies. In a Truth Social post, Trump accused Canada of "wilful negligence" and said the United States was being "invaded by filthy, polluted, and unhealthy air." He pledged to call Prime Minister Mark Carney to demand answers. The White House did not respond to questions about what legal mechanism would be used to impose such tariffs or how the rate would be calculated.

The United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!

Smoke blankets the US

Smoke from 896 active fires across Canada has covered a wide swath of the United States, from the Midwest to the Northeast. More than 100 million people in 18 states and the District of Columbia are under air quality alerts, with Detroit, Chicago, Washington DC and New York recording the worst air quality of any city in the world on Friday. In Ontario alone, roughly 200 fires are burning, 81 of them out of control, and 650,000 acres have been scorched. At least one remote community has been completely destroyed, and members of the Namaygoosisagagun First Nation are "distraught" after fires tore through with little warning.

Canadian officials push back

Prime Minister Carney responded on Thursday that "fighting climate change is the responsibility of all countries, including the United States." Ontario Premier Doug Ford was more direct on Friday, telling American critics to offer help rather than complaints. "Maybe what you should do rather than complain is send support, send help," Ford said. "Because we have done the exact same thing for our American friends, and that's what you're supposed to do." Ford also announced Ontario would purchase 11 new aircraft to combat the rapidly spreading fires.

Maybe what you should do rather than complain is send support, send help.

Republican lawmakers join pressure

The tariff threat was echoed on Capitol Hill. Senator Bernie Moreno of Ohio said he would introduce a bill next week "to sanction Canada and the responsible Canadian government officials for this atrocity." Four Republican members of the House from Michigan, a state that shares a maritime border with Ontario, wrote to Carney warning that if Canada does not manage its forests, "the United States will look elsewhere, and act on our own, to protect our people."

World Cup final concerns

The smoke has raised questions about Sunday's World Cup final between Argentina and Spain in East Rutherford, New Jersey. The White House is holding informal meetings with FIFA officials about the potential impact. Footage showed the stadium nearly vanishing in the haze, though it remains unclear how severely the match will be affected.

A pattern of tariff threats

Trump has repeatedly used tariff threats to pressure Canada since returning to office in January 2025, pushing for border security changes and trade practices he deems unfair. He has also suggested Canada should become the 51st US state. The US Supreme Court has already ruled many of his earlier tariffs on Canadian goods unconstitutional. During his first term, Trump similarly blamed California for wildfires, suggesting the state should have raked its forest floors, and he attacked Governor Gavin Newsom during the 2025 Los Angeles fires over water management and endangered species protections.