Canadian wildfires bring smog to Washington, DC area (screenshot via NBC)

President Trump on Friday vowed to hold Canada responsible for the “filthy, polluted, and unhealthy air” as smog and air pollution sweep across the Northern US.

“They are not properly maintaining their Forests and Brush therein, and the United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous and totally unacceptable!” Trump said.

“Canada has refused to engage in basic Forest Management and Debris Removal, knowing that such refusal will lead to exactly this result. This is Willful Negligence, and becoming a yearly occurrence, costing the United States Billions of Dollars, which cost of this pollution must of necessity be added to the TARIFFS Canada is currently paying,” the President said.

Nearly 900 fires are raging across Canada, bringing dangerous air quality to US states and major cities, including Washington, DC.

Canadian firefighters are attempting to extinguish the massive blazes, sending the smoke south into over a dozen US states.

Via Fox:

DC Mayor Muriel Bowser warned on Friday that older adults, children, “pregnant people,” and individuals with heart or lung diseases are most at risk from the unsafe air in the Capital.

Air quality in Washington, DC is unsafe right now, especially for sensitive groups.

Groups at highest risk include:

• Older adults (over age 65)
• Children
• Pregnant people
• Those who have heart disease, asthma, or other chronic lung disease

— Mayor Muriel Bowser (@MayorBowser) July 17, 2026

More from NBC 4:

The New York Times reported,

A plume of dense wildfire smoke stretched into the U.S. capital on Friday, as some of the worst air pollution on record in Washington blotted out the view of its stately monuments. Emergency rooms across the Northeast noted a spike in patients, and cities including Detroit handed out filtration masks as breathing outdoors remained unhealthy for tens of millions across North America.

Blazes continued to spread out of control across parts of central Canada and the boundary waters of northern Minnesota, with little sign that they would wane anytime soon. The authorities reported more than 20 new wildfires emerging overnight in the Canadian province of Ontario, where 191 were burning as of Friday morning.

Advancing weather systems are expected to help sweep away some of the stifling heat and smoke from the worst-hit parts of the United States on Friday, at least for a little while, including in Toledo, Detroit, Milwaukee and New York City. But smoke could return to those same places this weekend.

President Trump wrote in a Truth Social post on Friday,