Lloyd Austin underwent new hospital treatment for bladder problem

The US defense secretary, Lloyd Austin, underwent hospital treatment for a bladder issue for the second time in just over three months, the Pentagon announced.

A Pentagon spokesperson, Maj Gen Pat Ryder, said the 70-year-old Austin entered Walter Reed military medical center on Friday evening to undergo what he called “a scheduled, elective, and minimally invasive follow-up non-surgical procedure” to treat his previously disclosed bladder condition.

While he was under treatment, Austin delegated his duties to his deputy, Kathleen Hicks, who assumed the role of acting defense secretary. Later Friday, the Pentagon said Austin had resumed his normal duties.

Related: Lloyd Austin to resume Pentagon duties one day after admission to hospital

The statement added: “The secretary’s bladder issue is not related to his cancer diagnosis and has had no effect on his excellent cancer prognosis. White House and congressional notifications have occurred.”

Austin was previously admitted to the Walter Reed facility on 12 February to treat what was then called “an emergent bladder issue”.

The Pentagon’s announcement follows an outcry in January after it emerged that Austin had spent three days in hospital – including a spell in intensive care – following complications arising from prostate cancer surgery that was not initially disclosed to Joe Biden, the president’s national security council or the US joint chiefs of staff.

Republicans called for Austin’s resignation, pointing out that he had been out of action at a time when US forces were facing threats from Iran-backed militias in Iraq and Syria. The Pentagon said the non-disclosure was partly attributable to one of Austin’s senior staff members being ill with flu at the time.

Frustration only intensified after it emerged that Biden had not been informed of Austin’s cancer diagnosis, for which he was originally treated under general anaesthetic at Walter Reed on 22 December, before having to be readmitted 10 days later after experiencing painful symptoms.

The White House later criticised Austin’s “lack of transparency” but kept him in his post after he acknowledged responsibility. The national security council spokesperson, John Kirby, said at the time that the episode had prompted a review of procedures.