Omicron continues to disrupt travel plans in US

The latest COVID-19 variant is upending holiday plans for tens of thousands of travelers in the US.

Airlines canceled hundreds more flights on Sunday, citing staffing problems tied to COVID-19, as the nation's travel woes extended beyond Christmas, with no clear indication when normal schedules would resume. More than 700 flights entering, leaving or flying within the US were called off, according to the flight-tracking website FlightAware.

More than 50 flights were already canceled for Monday. Delta, United and JetBlue have blamed the omicron variant of the coronavirus for staffing shortages that forced cancellations. JetBlue scrapped 10% of its flights Sunday.

Delta canceled 5% and United canceled 4%, according to FlightAware. The three airlines canceled more than 10% of their scheduled flights on Saturday.