Shawn Mendes has come under fire for using a photo of New York engulfed in smoke from wildfires to promote his new single.

He posted a photo on Thursday of the Manhattan skyline, which had been rendered almost invisible by smoke from wildfires in Canada - less than 36 hours after it happened.

The words "What the hell are we dying for" were placed on the photo.

"People are dying in fires and getting sick from poor air quality and you've decided to make it look aesthetic?" someone wrote. "Why are you trying to profit from a natural disaster?" said another.

"Did he commercialize New York's climate?" reads in a next comment.

Tens of millions of people in North America were warned of hazardous air quality as intense wildfires raged across Canada. New York and Ottawa recorded the worst air quality on Wednesday, reaching "hazardous" levels.

Public health officials warned people not to exercise outdoors and to minimize exposure to smoke as much as possible.

Thousands of people have been evacuated across Canada and the fires have burned more than 3.3 million hectares of land. Canadian officials say the country is bracing for its worst wildfire season on record.