The Federal Aviation Administration has implemented a ground stop for flights bound for New York's LaGuardia airport due to smoke.

Flights going to LaGuardia are being kept at their departing airports until 2 p.m. EDT, according to a FAA bulletin. The FAA says the chance of an extension is "low," but delays could follow.

All flights bound to Newark Liberty International Airport are being delayed from taking off from their departing airports until 11:59 p.m. EDT. An FAA advisory cites "low visibility" as the cause.

As of 1:00 p.m. ET, airlines in the U.S. have canceled 74 flights and delayed another 1,257, according to data from tracking site FlightAware.

The Federal Aviation Administration says the extreme wildfire smoke haze lingering over the Northeast U.S. due to Canadian wildfires could delay flights through Boston, New York, Philadelphia, Baltimore, and Washington, D.C.