Washington DC - As Covid-19 cases rise in the US, many airlines are feeling the brunt, with more holiday week flights being cancelled and Dr Anthony Fauci's recent call for unvaccinated people to avoid domestic air travel only adding to the challenges.

As a result of the travel problems, many people were still stranded at airports on Tuesday as their flights were cancelled and there was confusion over what to do next, according to reports.

Airlines worldwide have been facing staff issues for many weeks as the highly infectious Omicron variant spreads rapidly.

According to official figures, the average number of new US cases over the past week has risen more than 55% to 205,000 per day.

On Sunday, Dr Fauci recommended a vaccine mandate for domestic travel, although President Joe Biden has yet to voice his support for the plan.

On Monday, Fauci clarified the remarks, saying it was only something "on the table" as a discussion, but that it "doesn't mean it's gonna happen."

"I doubt if we're gonna see something like that in the reasonably foreseeable future," he said.

The Center for Disease Control (CDC) on Monday reduced the quarantine recommendations for asymptomatic cases from ten to five days of isolation.

Due to staffing shortages, Delta Air Lines had been putting pressure on the CDC to make the move for those with breakthrough cases – which received pushback from the flight attendant union.

Along with the Omicron variant, weather issues further disrupted the travel plans of many travelers on Monday.

The flight cancellation chaos has been ongoing since Friday, citing more than 4,000 flights within the US that have been grounded since Christmas weekend.