Austin has been hospitalised in the critical care unit for complications from prostate cancer.

Austin, 70, was taken to Walter Reed Military Medical Center on Sunday with “symptoms suggesting an emergent bladder issue”, the Pentagon said.

Austin was scheduled to travel to Brussels on Tuesday to attend a regular meeting of the Ukraine Defense Contact Group, a group of about 50 countries, to coordinate military aid for Kyiv. That meeting will now be held virtually, two US defence officials told The Associated Press news agency on the condition of anonymity.

After the Ukraine meeting, Austin was to attend a regular meeting of NATO defence ministers, also in Brussels. It is not immediately clear if Deputy Defense Secretary Kathleen Hicks, who Austin has transferred his duties to, will attend that meeting instead.

Austin had failed to disclose a prostate cancer surgery in December and a subsequent hospitalisation in January to deal with its complications. This month, the cabinet secretary apologised for failing to tell Biden and senior staff about his cancer diagnosis, adding that the health scare was a “gut punch” that had shaken him.

The most recent hospitalisation was publicly announced soon after he was taken to the military medical centre by his security detail.

Austin is scheduled to testify before Congress on February 29 about the secrecy surrounding his initial hospitalisation.

His trip to Brussels would have come at a critical time in Europe.

A narrowly divided US Senate moved closer to passing a $95.3bn aid package for Ukraine, Israel and Taiwan on Sunday, showing undiminished bipartisanship despite mounting opposition from Republican hardliners and former US President Donald Trump to continued help to Ukraine.

The legislation includes $61bn for Ukraine, which is viewed as crucial by Kyiv as it grinds towards the second anniversary of Russia’s full-scale invasion as front lines in eastern and southern Ukraine largely static for many months.

Trump, who is seeking a return to power in the November presidential election, raised a storm of criticism from the White House and top Western officials over the weekend for suggesting he would not defend NATO allies who failed to spend enough on defence and would even encourage Russia to attack them.