A White House official warned that the federal government could end up having to spend up to $22 million a month on testing employees for COVID-19 if the ban on President Biden's vaccine mandate isn't lifted.

Jason Miller, deputy director for the White House Office of Management and Budget, gave the assessment in a declaration cited by the Department of Justice on Monday, Reuters reported.

"While most federal civilian employees are fully vaccinated, hundreds of thousands of them are not vaccinated," Miller said in declaration made late last month. According to Miller, the federal government hires about 20,000 new employees every month and is unable to require them to get vaccinated.

Last month, a federal judge in Texas blocked Biden's vaccine mandate for federal workers, ruling that the mandate exceeded his authority as U.S. president.

Currently, workplace safety protocols requires federal employees to get tested weekly for COVID-19 if they are unvaccinated.

According to Miller, this requirement "could cost taxpayers on the order of $11 million to $22 million each month, or $33 million to $65 million each quarter."

He added that if the block on the vaccine mandate remains in place, "it will imperil the federal government's ability to protect the health and safety of the federal workforce."