United States carriers Delta Air Lines and Alaska Air Group have cancelled hundreds of flights due to adverse weather conditions and rising cases of the Omicron variant.

Delta said it expected to cancel more than 250 of 4,133 scheduled flights, while Alaska cancelled 170 flights across its network and warned of more cancellations and delays throughout the week, Reuters reported.

Total cancellations as of 14.00 ET within, into, or out of the United States stood at 1,034, with 2,694 flights delayed, marking a fifth day of flight cancellations.