Covid-19: US airlines cancel more than 200 flights amid Omicron surge

America's United Airlines and Delta Air Lines on Thursday said they had each cancelled dozens of Christmas Eve flights, as the spreading Covid-19 Omicron variant takes a toll on its flight crews and other workers.

Chicago-based United cancelled 120 flights for Friday, while Atlanta-based Delta said it has cancelled about 90. Both said they were working to contact passengers so they would not be stranded at airports.

"The nationwide spike in Omicron cases this week has had a direct impact on our flight crews and the people who run our operation. As a result, we’ve unfortunately had to cancel some flights and are notifying impacted customers in advance of them coming to the airport," United said.

Delta said it has "exhausted all options and resources -- including rerouting and substitutions of aircraft and crews to cover scheduled flying -- before cancelling around 90 flights for Friday."

Delta cited potential inclement weather and the impact of the Omicron variant for the cancellations.