Trump threatens new Canada tariffs over wildfires sending 'filthy' air into US cities

US President Donald Trump has threatened to impose new tariffs on Canada after hundreds of wildfires have left much of the northern US covered by a blanket of smoke. According to the Canadian Wildland Fire Information System, about 955 fires were actively burning across Canada as of Saturday, with the majority out of control. More than 190 of those blazes are burning in Ontario, some out of control.

Trump posted on Truth Social that he would call Canadian Prime Minister Mark Carney to demand an explanation for Canada's 'willful negligence', accusing the country of 'not properly maintaining' their forests and brush. Fellow Republicans have used the issue to renew Trump's call to make Canada the 51st US state. Ontario Premier Doug Ford asked the US to send support to fight the fires rather than complain.

Canadian officials said the country has invested about C$12 billion ($8.5 billion) in forest sustainability and fire prevention. Carney earlier noted that it was the responsibility of both countries to fight climate change. After Trump's remarks, Carney's emergency management cabinet minister said the two countries remain in constant contact and share a long history of working together on such disasters, citing a reciprocal fire-fighting agreement from 1982.

The smoke has impacted many US states, from Minnesota and Michigan to New York and Ohio. Air quality in Detroit was worst in the world on Friday, according to Swiss air quality tracker IQAir, followed by Chicago and Washington DC. New York ranked seventh. 'Hazardous' air quality alerts have been issued across the region, leading to the cancellation of many outdoor events.

Scientists say increasingly severe wildfire seasons are being driven in part by climate change, which creates hotter, drier conditions. Some fires have also been sparked by lightning. 'Climate change is a global issue, and it would be inaccurate to suggest that Canada alone caused or could have prevented these wildfires,' said Dr Anabela Bonada from the University of Waterloo.

Ford dismissed criticism from US lawmakers, noting that Canada has previously assisted the US in battling wildfires in California and responding to hurricanes in North Carolina. 'That's what neighbors do,' he said. 'You don't get on and start threatening and criticizing because guess what? One day it's going to be your turn, and we're going to be down there without hesitation to support our neighbors.'

One affected community is the Namaygoosisagagun First Nation in northern Ontario. Chief Helen Paavola told local media that an aerial flyover showed the community has been 'burnt to ashes'. Ford said a total of 10 communities have had to evacuate and called it a miracle that no lives were lost.

Poor air quality has led to cancellations of summer camps, concerts, and other outdoor activities. Low-visibility conditions at airports caused flight delays. Concerns were raised about Sunday's World Cup final in New Jersey, but forecasters expect weekend rains to improve conditions.