US President Donald Trump has threatened to impose new tariffs on Canada, accusing the country of allowing wildfire smoke to pollute American cities with what he described as "filthy" air.
The comments came as massive wildfires continued to burn across parts of Canada, sending thick smoke into several US states and worsening air quality from the Midwest to the East Coast.
Canadian leaders rejected the criticism, saying the country is using every available resource to battle the fires and urged the United States to provide assistance instead of blaming Canada.
Ontario Premier Doug Ford said Canada has repeatedly helped the US respond to natural disasters, including wildfires in California and hurricanes in North Carolina.
"Maybe what you should do rather than complain is send support, send help, because we have done the exact same thing for our American friends," Ford said.
Ford noted that the US states of Michigan and Massachusetts have already offered help by sending water bombers, firefighters and rescue teams.
Canadian Prime Minister Mark Carney also responded, saying climate change is a shared global challenge.
"Climate change is everyone's responsibility — including the United States," Carney told reporters, adding that his government remains in close contact with provincial authorities and affected communities.
Ford defended Ontario's response, saying more than 150 firefighting crews, over 80 water bombers and helicopters have been deployed to contain the blazes.
"We are throwing every single resource we can," he said.
Wildfires continue to spread
Several communities in northern Ontario have been evacuated as fires continue to spread. A First Nations leader said one community had been "burnt to ashes."
Wildfires are also raging in British Columbia, where officials reported more than 59 active fires on Friday. The British Columbia Wildfire Service said 39 new fires started within the previous 24 hours, while 31 remain out of control.
A large group of fires in northwestern Ontario has produced massive smoke clouds that have spread across Canada and into the United States.
Smoke disrupts daily life across US
Heavy smoke reduced visibility in New York City on Thursday, partially obscuring landmarks including the Empire State Building and the Statue of Liberty. Similar hazy conditions affected Washington, DC, where national monuments were barely visible.
Health officials advised residents to stay indoors, while some communities distributed free face masks because of the health risks linked to poor air quality.
The smoke also forced the cancellation of outdoor activities across parts of the northern United States, including Chicago, Detroit, Pennsylvania and New England. Summer camps moved activities indoors, concerts were postponed and at least one popular lakeside beach was temporarily closed.
Poor visibility also disrupted air travel, causing flight delays at several airports.
Concerns ahead of World Cup final
The wildfire smoke has also raised concerns ahead of Sunday's FIFA World Cup final between Argentina and Spain at MetLife Stadium in New Jersey, which President Trump is expected to attend.
US officials, including Andrew Giuliani, who heads the White House World Cup Task Force, have been holding informal discussions with FIFA and other agencies monitoring the wildfire situation.
However, weather forecasts suggest rainfall over the weekend is expected to improve air quality before kickoff.
Meanwhile, residents of several First Nations communities in northern Ontario continue to evacuate as the fires advance. Videos shared online showed some families leaving remote areas by boat.
Matthew Hoppe, incident commander for the Namaygoosisagagun First Nation, said the community had been devastated after the wildfire spread with little warning.
Source: BBC