Defense Secretary Lloyd Austin will undergo a nonsurgical procedure Friday evening at Walter Reed Medical Center as a follow-up for a bladder issue he had earlier this year, the Pentagon said in a release.

The procedure is unrelated to his cancer diagnosis. 

The Pentagon said the White House and Congress have been notified, and that Austin will be temporarily unable to perform his duties during the procedure. 

As a result, "Deputy Secretary of Defense Kathleen Hicks will assume the functions and duties of the Secretary of Defense, and serve as the Acting Secretary of Defense," the Pentagon said.

Austin was diagnosed with prostate cancer and hospitalized in December, but didn't tell the White House for several days at the time.