Deputy press secretary Sabrina Singh said Austin was in "good condition" and was expecting to be "released from the hospital later today."

"So we will provide an update on when that occurs, and when he resumes his full duties and functions," she added.

Austin was admitted to a critical care ward on Sunday and transferred duties to his deputy.

The 70-year-old's latest health scare came weeks after it emerged he had kept recent hospital stays secret and had not promptly informed President Joe Biden of his cancer diagnosis, sparking widespread criticism.

He "underwent non-surgical procedures under general anesthesia," his doctors at the Walter Reed National Military Medical Center outside Washington said Monday in a statement.

Austin is a key figure in efforts by the United States to shore up Western support for Ukraine's fight against Russia's invasion, as Republican lawmakers in Washington refuse to fund new military aid to Kyiv.

He had been scheduled to attend a meeting in Brussels of the Ukraine Defense Contact Group of nations coordinating the military assistance, but the Pentagon canceled those plans and announced the meeting would instead be virtual.

Singh said Austin was still planning to give opening remarks at the virtual version of the gathering.