20,000 flights cancelled in US since Christmas Eve: The Hill

Among them were 1,760 flight cancellations within, into or out of the country on Wednesday, said the report by The Hill.

Meanwhile, more than 4,800 flights were delayed on Wednesday, it said.

"Airlines for weeks have been forced to cancel flights because of staff shortages driven by the surge in COVID-19 cases nationwide and inclement weather across the country," said the report.

The United States registered 791,734 new cases and 1,989 more deaths on Thursday, bringing the national counts to more than 58 million and 831,729 respectively, according to data from the US Centers for Disease Control and Prevention.

Although the Biden administration has started to push for more people to get vaccinations, as well as boosters, the public seem not so actively responsive to the official calls.

On Thursday, The New York Times reported that although eligibility has greatly expanded for more Americans to get a booster shot, it "has not been met with an equal amount of demand. "Only about 35 per cent of Americans have received a booster since mid-August, when additional shots were first authorised," the report noted.