(Reuters] – FedEx Corp. (NYSE:) warned Friday that Omicron variant is increasing in severity and has resulted in staff shortages as well as delays to aircraft shipments.

According to the company, “The explosion of the COVID-19 Omicron version has created a temporary shortage in available crew members as well as operational staff.”

Delivery firm stated that severe winter storms across the country, including in Memphis, Tennessee are creating challenges. The company is developing contingency plans to adjust operations and implement contingency planning to reduce disruptions.

Extreme winter conditions and rapid spreading of Omicron variant, which is highly transmissible, have caused a dramatic rise in infection rates. Many airlines across the United States had to cancel their flights due to crew quarantine and pilot quarantine.

On Thursday, the U.S. was forced to resign due to insufficient staffing. Postal Service was one of the most important civilian employers in the U.S. and sought to temporarily rescind the new vaccination or testing requirements that the Biden administration had placed on large-scale businesses.

A Reuters count shows that U.S. deaths from coronavirus have increased by at most 2,133 to 836.901 total on Thursday, versus 834.768 the day before,