Airports in Toronto and Montreal pause departing flights after the FAA declared a nationwide ground stop in the US

• Two Canadian airports have issued ground stops on Friday.
• NAV CANADA, the organization that runs Canada's airspace system, said it's to "safely manage traffic."
• Many airport hubs will take on extra planes as airlines headed to the US divert.

Two airports in Canada — Toronto Pearson International Airport and Montréal-Trudeau International Airport— have issued ground stops amid the air traffic control outage in the US.

Both airports listed the reason as "other" in the Federal Aviation Administration airspace advisory. Toronto said the "probability of extension is high (greater than 60%)."

NAV CANADA, a privately run nonprofit corporation that owns and operates Canada's civil air traffic system, said Friday night that its systems are "operating normally" and that it issued ground stops to "safely manage traffic volumes."

Read more Business Insider coverage of the nationwide ground stop:

• FAA grounds air travel nationwide — more than 10,500 flights are delayed, and 2,700 are canceled, with no end in sight
• FAA SMART AI system vendor, Microsoft say ground stop wasn't their fault
• Photos show trouble at airports nationwide as FAA grounds all flights

"Travellers should expect delays and check with their airline," it said on X.

Mark Stephens, a retired Delta Air Lines pilot, told Business Insider that the airports may be preparing for US-bound international flights that need to divert.

He added that the planes on the ground at the airports will return to their gates, meaning traffic management will be imperative to handle the potential increase in volume.

As of 6:20 pm Eastern time, more than 2,700 flights have been canceled within, to, or out of the US, according to FlightAware.com. Another 10,500 have been delayed.

Cirium, an aviation analytics company, said at least 600 flights have been diverted so far on Friday, with airports like Denver, Chicago, Los Angeles, and Cleveland taking on additional flights.