These employees account for less than 1 percent of its US workforce, according to a company memo attached to the statement.
"I can also confirm that 593 employees chose not to comply with the vaccine requirement and as a result, we’ve started the process to separate them from the company," the statement said on Tuesday.
The company extended the deadline for those who applied for a medical or religious accommodation, the memo said, which media outlets reported as amounting to around 2,000. The company said they did so "in light of a pending court case."
American Airlines, Delta, and Southwest Airlines do not have a vaccine mandate for their employees.
Since January 2020, about 692,274 Americans have died from COVID-19 and more than 43.2 million infections have been reported nationwide, according to Johns Hopkins University.