JetBlue Airways is removing about 1,300 flights from its schedule between Thursday and the middle of January, in anticipation of crew members becoming sick with the Omicron COVID-19 variant -- which has already led to thousands of cancellations by various carriers worldwide over the past week.

JetBlue, which has already cut hundreds of flights in recent days due to the surge in Omicron infections, said it's cutting the future flights now to avoid last-minute cancellations that can cause severe difficulty for travelers and airports.

The lost flights will affect about 10% of JetBlue's schedule, the carrier said.

U.S. carriers including United, Delta and American have canceled more than 4,000 flights over the past week. Some were weather-related and the rest were due to insufficient staffing due to COVID-19 sickness.

"This past week has been one of our most difficult operating periods during the pandemic," three JetBlue department leaders wrote in a note to staff, according to CNBC.

"The exponential growth in Omicron cases over just a couple of days is at a level that no one could reasonably prepare for."

JetBlue canceled nearly 200 U.S. flights on Thursday while other carriers canceled hundreds more.

At the urging of airlines to shorten guidance for COVID-19 isolation, the Centers for Disease Control and Prevention said earlier this week that asymptomatic cases could isolate for only five days as opposed to 10.

JetBlue said it's hopeful that the new requirements will help bring sick staff back faster, but added that cases are peaking in the Northeast where most crew members are based.

Copyright 2021 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent., source US Top News