Washington | US President Joe Biden is heading to Walter Reed National Military Medical Center for a routine medical checkup, an event that is being keenly watched as the oldest president in history makes plans for an expected reelection campaign.

Biden, 80, last received a standard medical exam in November 2021. During that five-hour-plus visit, he went through a combination of blood, physical, gastrointestinal, dental, vision and neurological tests.

Afterward, Dr. Kevin O'Connor, who has been Biden's primary care physician since 2009, signed a six-page memo that called Biden “healthy, vigorous," and deemed him "fit to successfully execute the duties of the Presidency.” Many people, including Democrats, have expressed reservations about Biden seeking a second term in 2024. Only 37 per cent of Democrats say Biden should pursue reelection, down from 52 per cent prior to last year's midterm elections, according to a recent poll from The Associated Press-NORC Center for Public Affairs Research. Overall, 22 per cent of US adults said he ought to run again.

Follow-up interviews with people polled in the survey indicated that Biden's age was a major concern.

People took note of his coughing, a greater sense of fragility in his walking and moments when he misspoke.

During Biden's 2021 physical, a neurological exam found nerve damage to his hands and feet that had contributed to his stiffened gait. Spinal arthritis and compensation for a broken foot also caused him to walk more cautiously.

Biden underwent a colonoscopy in 2021, in which a 3 millimeter “benign-appearing polyp” was identified and removed.

Asked in a recent PBS interview about his age and ability to be president, Biden responded with what has become his stock line: “Watch me. It's all I can say.” Biden tested positive in July for COVID-19 and experienced “very mild symptoms,” according to the White House. The president continued to work even as he isolated himself in the White House.