Countries face record high daily new COVID-19 cases due to Omicron's spread Editor: Feng Qingyin/GT Graphic: Xu Zihe/GT

After a bruising holiday week of flight cancellations and record surges in COVID-19 cases, a powerful winter snowstorm Monday further snarled US transport, shuttering the federal government and bringing Washington to a standstill.

The storm packed an unexpectedly fierce punch and appeared to have caught much of the capital city off guard, temporarily stranding US President Joe Biden on Air Force One and dumping up to 23 centimeters of snow on Washington.

Many Americans have been scrambling to return home after the Christmas and New Year period, with thousands of flights canceled due to bad weather and airline staffing woes blamed in part on rising coronavirus infections among crews.

More than 4,900 flights Monday, the first workday of 2022, were canceled globally as of 8:30 pm (0130 GMT Tuesday), according to flight-tracking website FlightAware.

The latest cancellations - along with 6,775 US flight delays Monday - compounded holiday travel misery.

While much of the US Mid-Atlantic was caught in the bad weather, conditions were acute in the capital and neighboring states of Maryland and Virginia, where accumulation in some spots topped 12 inches, according to meteorologists who described it as the region's biggest snowstorm in at least two years.

"This is a heavy snow," said Mayor Muriel Bowser of Washington, where plows scrambled to clear snow, trees and power lines tumbled, the US Senate postponed votes and health officials canceled COVID-19 testing.

"If it is not absolutely necessary for you to go out, stay home and off the roads," she warned. 

Schools around the region were also closed due to snow.