Dr. Anthony Fauci suggested Thursday that a court did not have the authority to strike down the Centers for Disease Control and Prevention’s (CDC) mask mandate.

The comments from the director of the National Institute of Allergy and Infectious Diseases come after a federal judge, appointed by former President Donald Trump, ruled Monday that the mask requirement was “unlawful,” prompting a slew of airlines to drop their mask mandates.

U.S. District Judge Kathryn Kimball Mizelle said Monday in her ruling that the mandate “exceeded the CDC’s statutory authority, improperly invoked the good cause exception to notice and comment rulemaking, and failed to adequately explain its decisions.”

“I was both surprised and disappointed,” Fauci said of the court ruling, “because those types of things really are the purview of the CDC. This is a public health issue.”

“If you look at the rationale for that, it really is not particularly firm, and we are concerned about that, about courts getting involved in things that are unequivocally a public health decision,” Fauci continued during a CNN+ interview. “This is a CDC issue, should not have been a court issue.”

Fauci insisted that the CDC’s May 3 end to the mask date should have been honored.