Canada issues air quality warnings over US wildfire smoke after Trump tariff threat

Smoke from US wildfires has crossed into Canada, prompting air quality warnings in British Columbia, reversing the recent flow of smoke southward that had prompted President Trump to criticize Canada's fire management. Thousands of lightning strikes in the northeastern US have fueled fires whose smoke is now drifting north across the border. The situation highlights the cross-border nature of wildfire smoke pollution and comes amid Trump's recent threats of tariffs against Canada over fire management disputes.