The increasing number of Omicron cases continues to affect travel plans across the globe.

According to BBC News, over 1,400 flights have been cancelled worldwide on Monday morning.

BBC News cites the FlightAware data tracking website as saying that most of the canceled flights are in the United States and China.

In some cases, severe weather has disrupted flight schedules, but most of the cancellations in the U.S. are due to crewmembers testing positive or isolating.

At this time, the worst-hit US airlines appear to be United, with 84 cancellations, and JetBlue which had 66.

Hong Kong, meanwhile, is banning all South Korea's Korean Air flights for two weeks, after positive cases among some arrivals.

In total, more than 8,000 flights have been grounded over since Friday.

This number of cancellations is higher than normal for the holiday weekend.

According to the BBC, in the UK, British Airways has 42 cancellations on Monday and London's Heathrow airport has 47 scrapped flights.

US authorities are also monitoring dozens of cruise ships hit by coronavirus cases while sailing in the country's waters, several were reportedly denied port in the Caribbean, AFP news agency reports.

The uptick in COVID cases has largely been driven by the Omicron variant, health experts say.

Last week, United airlines warned that a spike in Omicron cases created, "a direct impact on our flight crews and the people who run our operation," leading to the self-isolation of many employees who came into contact with people who were infected. 

As of December, Johns Hopkins University reports that approximately 5.4 million people around the world have died due to coronavirus complications.