US President Joe Biden has been in the headlines again for his old age as he was witnessed tripping twice while boarding Andrews Air Force Base in Maryland Tuesday, reinvigorating the debates of his mental health and physical well-being.

The tripping comes months after Joe Biden stumbled as he made his way up the steps to board Air Force One despite using a facile short staircase.

The cameras captured the 81-year-old stumbling as he went on to his aeroplane, avoiding a fall.

The tripping has strengthened the demands for the evaluation of the mental abilities of the oldest president in US history.

Former US Ambassador to the UN and Republican presidential candidate Nikki Haley had been calling for the evaluation of the mental abilities of political leaders aged over 75 during her electoral rallies.

Last week, the independent contender for the White House Robert F. Kennedy Jr said: “Biden should come out and debate and to show the American public that he has the cognitive capacity to do this very, very difficult job.”

Republicans in Congress wrote a letter to Biden last week calling for his cognitive test to prove his mental fitness for the Oval Office.

The letter was led by the former White House physician and chief medical adviser to former President Donald Trump, Ronny Jackson, and co-signed by 83 House Republicans.

“Following the recent report from Special Counsel Robert Hur, we write to express our grave concerns with your current cognitive state and ability to successfully execute the duties of the Presidency, including as Chief Executive, Head of State, and Commander in Chief,” the lawmakers wrote in the letter.

“This is the fifth time we’ve sent a letter to the White House demanding Biden take a cognitive exam, however, while the administration has chosen to ignore each of these requests, it is becoming clearer each day that the President is not cognitively fit,” Jackson told Fox News Digital in a statement.

“I am proud to be joined by Conference Chairwoman Stefanik, Chief Deputy Whip Guy Reschenthaler and dozens of my House colleagues in this effort.”

Last year in June, President Joe Biden stumbled and fell after presenting the final diploma during a graduation ceremony at the US Air Force Academy.

With the help of three individuals, the 80-year-old president swiftly regained his footing and returned to his seat without assistance. As he was being assisted, Biden gestured behind him, indicating the object that caused him to trip.

According to White House communications director Ben LaBolt, who shared an update on Twitter, Biden sustained no injuries.

LaBolt clarified that a sandbag was present on the stage when Biden was shaking hands, leading to the stumble.