Canadian leader Mark Carney says both countries have a responsibility to fight climate change.

On Friday, President Donald Trump threatened to raise tariffs on Canada, blaming the country’s worsening wildfires for sending hazardous smoke across the U.S. and accusing Ottawa of failing to properly manage its forests.

US President Donald Trump has blamed Canada for wildfire smoke drifting into the United States and threatened consequences. The cost of the pollution "must of necessity be added to the TARIFFS Canada

U.S. President Donald Trump has claimed that Canada should face additional tariffs in response to worsening air pollution in the United States caused

Earlier, Ontario's Premier Doug Ford said America should send support rather than complain as smoke from more than 850 Canadian wildfires blankets parts of the US.

Soot from Canadian wildfires blanketed a dozen U.S. states Friday, as government agencies warned millions of Americans to stay indoors.

President Trump said Friday he's holding Canada responsible for wildfire smoke that's pushed air quality to hazardous levels across the Midwest and Northeast.

President Trump is indicating that he may punish Canada over wildfire smoke that’s drifted into the U.S. further inflaming tensions.