The recent surge in COVID-19 cases due to the omicron variant has wreaked havoc for Christmas travelers. On Friday and Saturday, a number of major airlines reported flight delays or cancellations in part due to pandemic-related staffing shortages.

According to Flight Aware, which monitors airlines and airports, 1,675 flights «within, into or out of the United States» were delayed and 947 flights were canceled as of 1:05 p.m. PT on Christmas.

This continued two previous days of problems. On Christmas Eve, a total of 3,695 US flights were delayed and 690 were canceled. On Thursday, there were 5,679 delays and 281 cancellations. United, Delta and JetBlue were the hardest hit US airlines.

United confirmed Friday that its flight issues were related to the omicron variant.

«The nationwide spike in omicron cases this week has had a direct impact on our flight crews and the people who run our operation,» the carrier said in a statement. «As a result, we’ve unfortunately had to cancel some flights and are notifying impacted customers in advance of them coming to the airport.»

In a blog post, Delta attributed delays to both omicron and winter.

«As winter weather impacts the northwest and northeast U.S. [and] the omicron variant continues to surge, Delta teams exhausted all options and resources before canceling around 158 flights in Friday’s nearly 3,100-flight schedule,» Delta said Friday. «Delta people are working together around the clock to reroute and substitute aircraft and crews to get customers where they need to be as quickly and as safely as possible.»

Delta said it expects an increase in cancellations to continue through the weekend.

JetBlue didn’t immediately respond to a CNET request for comment.

Separately, the White House reportedly will lift a ban on travel from eight countries in southern Africa, where the omicron variant was originally detected. The restrictions, which were put in place last month, covered most non-U.S. citizens who had recently been in Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa or Zimbabwe. The restrictions will be lifted on Dec. 31.

CNET’s Andrew Morse contributed to this report.