The President of the United States, Donald Trump, threatened to raise tariffs on Canada to offset the impacts of pollution caused by smoke from forest fires, which reached New Jersey, where the World Cup final will be played this Sunday (19). One of the regions most affected by fires in Canada generated a huge cloud of smoke that darkened the sky in neighboring areas of the states of New York and New Jersey. The latter will host the match between Spain and Argentina at MetLife Stadium in East Rutherford. World Cup organizers "are closely monitoring the situation", said the executive director of the White House World Cup working group, Andrew Giuliani, during a press conference. Dense plumes of smoke coming from Canada and northern Minnesota led to poor air quality warnings being issued in several regions of the United States. So far, there are no records of victims. A total of 937 fires remained active Saturday in Canada, most of them out of control, according to the Canadian Wildfire Information System. "This is 'Deliberate Negligence' and it is becoming a recurring problem, costing the United States billions of dollars," Trump wrote on his social media site, Truth Social. The American president accused Canada of "failing to adequately care" for its forests and of failing to carry out "basic forest management and waste removal tasks." "The cost of this pollution needs to be included in the TARIFF that Canada currently pays," he added. The Republican also said he intended to call Canadian Prime Minister Mark Carney "to find out what they're going to do" about the smoke. Canadian Minister of Emergency Management, Eleanor Olszewski, stated that her country maintains "constant contact" with the United States and highlighted the "long history of cooperation in combating forest fires". She also highlighted that Canada has invested US$12 billion (about R$61.4 billion) in forest sustainability and fire prevention since 2020. The Statue of Liberty in New York Harbor is seen through a layer of wildfire smoke in Jersey City, New Jersey, USA, on July 16, 2026. REUTERS/Mike Segar A suffocated country Detroit, in the Midwest of the United States, remained the city with the most polluted air in the world, according to the IQAir monitor. Washington and Chicago appeared close behind in the rankings, and authorities recommended that the population avoid outdoor activities, except when strictly necessary. In New Jersey and the neighboring state of New York, the metropolitan region recorded air quality levels considered potentially harmful for more sensitive groups, although the situation improved after the intense fog that, on Thursday, almost made the Manhattan skyline invisible. Peter Mullinax, a meteorologist with the US National Weather Service (NWS), told AFP that winds over the Great Lakes region could push more smoke to the Northeast, keeping the sky overcast. According to Joel Dreessen, a meteorologist in Maryland, the main concern for Sunday's match is that "some models are already beginning to indicate that part of this smoke could be moved south," he told AFP. New York/New Jersey Stadium, in East Rutherford, in the United States, this Friday (17), two days before the 2026 World Cup final between Spain and Argentina. Paul Ellis/AFP Traveling toxicity In cities across the Midwest and Northeast of the United States, many people have taken to wearing masks outdoors to protect themselves from pollution. In New York, libraries and train stations distributed masks for free. Chris Carlsten, a researcher at the University of British Columbia who studies the health effects of wildfire smoke, told AFP that the fine particles present in smoke mainly affect the lungs, while pollution associated with vehicle traffic tends to cause more cardiovascular problems. He further explained that smoke clouds can contain paint, plastic and metal residues, as well as particles from burning wood and vegetation. The region formed by the states of Michigan, Minnesota and Wisconsin, known as the Upper Midwest and closest to the fires, faces especially severe conditions, with air quality levels classified as "dangerous".