Pakistan, July 18 -- US President Donald Trump has threatened to impose additional tariffs on Canada, arguing that the economic impact of wildfire smoke drifting into the United States should be considered in future trade measures.

Read More: House votes to overturn Trump's Canada tariffs

Speaking during a primetime address on Friday, Trump said the cost of pollution caused by Canadian wildfires "must" be factored into the tariff structure already applied to Canadian goods. He suggested Canada should bear responsibility for the cross-border effects of the ongoing wildfire crisis.

The remarks came as Canada continues to battle more than 800 active wildfires, with over 100 fires concentrated in northwestern Ontario. Thick smoke from the ...