President Trump faced new questions about his health on Sunday, after videos emerged of him gingerly walking down a ramp at the US Military Academy at West Point and having trouble bringing a glass of water to his mouth during a speech there.

Trump — who turned 74 on Sunday, the oldest a US President has been in his first term — was recorded hesitantly descending the ramp one step at a time after he delivered an address to graduating cadets at the New York-based academy on Saturday. The academy’s superintendent, Lieutenant General Darryl A. Williams, walked alongside him. Trump sped up slightly for the final three steps, as he got to the bottom.

Another video circulated of Trump taking a sip of water from a glass tucked inside his lectern on the dais at West Point. Trump held the glass with his right hand and brought it to his mouth, but appeared to momentarily have trouble lifting his arm farther. He used his left hand to push the bottom of the glass so that it reached his lips.

Trump posted defensively on Twitter late on Saturday night about the video circulating of his walk, and offered a description that did not match the visuals.

“The ramp that I descended after my West Point Commencement speech was very long & steep, had no handrail and, most importantly, was very slippery,” Trump wrote. “The last thing I was going to do is ‘fall’ for the Fake News to have fun with. Final ten feet I ran down to level ground. Momentum!”

There was no evidence that the ramp was slippery, and the skies were clear during the ceremony.

The videos again raised questions about the health of Mr. Trump, whose advisers have never fully explained his abrupt visit to Walter Reed National Military Medical Center in November, saying at the time only that it was intended to get a jump on his annual physical.

The White House doctor released a memo this month that summarised Trump’s yearly check-up, but provided little information beyond blood pressure (normal) and a description of his course of hydroxychloroquine as a prophylactic after the President was exposed to two staff members who tested positive for the coronavirus. The summary was not the customary report released in the past by Trump and other Presidents after a physical.

Trump’s difficulty traversing stairs and ramps has come up before, most notably in January 2017, when he clutched the hand of Theresa May, then the British Prime Minister, as they walked at the White House.

The President has frequently tried to raise questions about the health and mental fitness of his rivals, while growing indignant when his own is questioned.

Most recently, he and his allies have questioned the mental acuity of the presumptive Democratic nominee, former Vice-President Joseph R. Biden Jr, who is 77. But Trump spent much of the general election in 2016 challenging the “strength and stamina” of his Democratic rival at the time, Hillary Clinton, who suffered a bout of pneumonia and was videotaped unsteadily being led into a van at the annual ceremony at the World Trade Center site to commemorate the victims of the September 11 attacks.

Trump’s personal physician before he was President, Dr Harold N. Bornstein, has said publicly that Trump dictated a note the doctor wrote about his fitness when he was a candidate.

“If elected, Trump, I can state unequivocally, will be the healthiest individual ever elected to the presidency,” the doctor wrote in the note, which was released in December 2015.

New York Times News Service