US hit by smoke from out-of-control wildfires across the border in Canada

A man talks on his phone as he looks through the haze at the George Washington Bridge in Fort Lee, New Jersey (AP Photo/Seth Wenig)

Smoke from Canadian wildfires poured into the US east coast and mid-west on Wednesday, covering the capitals of both nations in an unhealthy haze, holding up flights at major airports, postponing Major League Baseball games and prompting people to fish out pandemic-era face masks.

While Canadian officials asked other countries for additional help fighting more than 400 blazes nationwide that already have displaced 20,000 people, air quality with what the US rates as hazardous levels of pollution extended into central New York and north-eastern Pennsylvania.