President Donald Trump said on Friday that he intends to charge Canada over wildfire smoke entering the U.S.

“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 posted on his Truth Social media platform Friday.

Smoke blowing down from Canada has clouded skies above East Coast states including New York as well as the Midwest throughout the week.

Trump added that he intends to call Canadian Prime Minister Mark Carney to ask how he plans to address the “incalculable” cost Canada’s fires have cost Americans. Trump suggested the damages ran into billions of dollars annually.

“Canada has refused to engage in basic Forest Management and Debris Removal, knowing that such refusal will lead to exactly this result,” the 80-year-old Republican continued.

Trump called those allegations an act of “willful negligence” in his message indicating that he would increase tariffs on Canadian goods purchased by U.S. consumers to offset costs.

Carney suggested actions rather than threats might be helpful.

“If there’s some politicians out there chirping away, well, maybe what you should do rather than complain is send support, send help, because we have done the exact same thing for our American friends,” the Canadian leader told reporters on Friday. “That’s what you’re supposed to do.”

Canadian outlet Global News listed several examples of times that Canada recently volunteered to help the U.S. fight fires on Friday. That short rundown included massive 2020 and 2025 blazes in California.

The president famously criticized California politicians for not “raking and cleaning” forest floors when fires devastated parts of that state before the 2020 inferno that killed 33 people and burned through more than 4,000 acres of land. He claimed to have discussed the matter with former Finnish Prime Minister Sauli Niinistö, who told local media he had no recollection of suggesting such methods of fire prevention.

Trump is one of several Republican politicians to have blamed Canada for wildfire smoke choking parts of the U.S. in recent days.

Mayor Zohran Mamdani, a Democrat, advised New Yorkers to avoid outdoor activities Thursday while a code red air quality alert was in effect as a result of fires burning north of the U.S. border.

Trump has been antagonistic toward Canada since being reelected to the presidency in 2023. In addition to repeatedly suggesting the 41-million person nation may be annexed by the U.S., he imposed tariffs making Canadian goods less affordable for American consumers shortly after returning to power. Canadians have responded by boycotting U.S. goods.