Trump threatened new Canada tariffs, blaming wildfire smoke for hazardous US air quality.
Around 888 Canada wildfires have burned nearly three million hectares this year.
Ottawa defended wildfire response, citing climate change and decades of US-Canada cooperation.
US President Donald Trump has threatened to impose new tariffs on Canada over hundreds of wildfires burning across the country, accusing Ottawa of wilful negligence after thick smoke spread across large swaths of the northern United States.
Trump said on Truth Social that the US was being unnecessarily invaded by filthy, polluted and unhealthy air, and that he would call Canadian Prime Minister Mark Carney to demand an explanation over the country's failure to properly maintain its forests. The remarks prompted a sharp response from Ontario Premier Doug Ford, who told US lawmakers to send help rather than complaints, pointing out that Canada had assisted American states during wildfires in California and hurricanes in North Carolina.
As of Friday, around 888 fires were actively burning across Canada, according to the Canadian Wildland Fire Information System, with more than 190 of those in Ontario alone and the majority burning out of control. Nearly three million hectares of land have already been destroyed. Smoke has spread across Minnesota, Michigan, Pennsylvania, Ohio and New York, with hazardous air quality alerts issued across much of the region. Detroit recorded the worst air quality in the world on Friday, according to Swiss tracker IQAir, followed by Chicago, Washington DC and New York in seventh place.
Ottawa defends its record
Four Republican lawmakers wrote an open letter to Canadian officials saying their patience had run out, claiming chronic under-investment in forest management and inadequate enforcement against arson had gone unaddressed year after year and that American lungs were paying the price. Scientists, however, told BBC Verify the picture was considerably more complicated than that framing suggested.
Canada's emergency management minister pushed back against the criticism, noting that the two countries had a long history of cooperation on such disasters, including a reciprocal firefighting agreement dating to 1982. Canada had invested roughly twelve billion Canadian dollars in forest sustainability and fire prevention, MP Eleanor Olszewski said, adding that the challenge was one that knew no borders. Carney, speaking in French at a news conference, said climate change was everyone's responsibility, including the United States.
Ford said more than 150 fire crews were on the ground alongside over eighty water bombers and helicopters, and that his government had spent more than a billion dollars on wildland fire management since 2018.
Relations between Ottawa and Washington have remained tense over trade, with no deal yet reached following tariffs Trump imposed on Canada last year.
