NEW YORK, Dec. 26 (Xinhua) -- Delta Air Lines, United Airlines, JetBlue Airways and American Airlines canceled more than 750 flights combined on Christmas Day, and cancellations were set to drag on through Sunday, upending plans during one of the busiest travel periods of the year, major U.S. media reported.

"All four airlines said Omicron cases among staff were driving cancellations," said USA Today on Sunday. "A combination of issues, including but not limited to inclement weather in some areas of the country and the impact of the Omicron variant, are driving cancellations and potential delays," said Delta in a statement.

"Holiday travel is generally a stressful enterprise, but a rapid surge in cases of COVID-19 caused by the Omicron variant have caused hundreds of flight cancellations, adding another layer of difficulty to the proceedings," reported NBC, noting that several major airlines are dealing with a shortage of workers.

"Major U.S. airlines canceled hundreds of more flights on Sunday, the third day in a row of mass cancellations and delays over Christmas weekend, as staff and crew call out sick amid the Omicron surge," reported CNN, adding that almost 700 U.S. flights were canceled and another 1,300 were delayed on Sunday.