The 81-year-old US president referred to a military cemetery in Italy, which is actually in France

US President Joe Biden confused Italy and France at a campaign event in New York on Saturday, in what appears to be the aging leader's latest gaffe, adding to mounting concerns over his mental state.

Speaking at a campaign reception in East Hampton, Biden mixed up the European countries when referring to a military cemetery near Paris where more than 2,200 US soldiers who fought in World War I are buried.

Biden said that former US President Donald Trump had called America's war dead "losers" and "suckers" - an allegation Trump denies - when he canceled a visit to Aisne-Marne American Cemetery in 2018. At the time, Trump's team blamed the decision to skip the visit on bad weather conditions.

Recalling the incident on Saturday, Biden said Trump had refused to visit the soldiers who had "given their lives in a cemetery in Italy." His remarks were later corrected with strikethroughs and brackets on the official White House transcript.

"He had called the veterans who had given their lives in a cemetery in Italy [France] - he wouldn't go to the cemetery, and - because he said they're a bunch of "suckers" and "losers," Biden said. "Well, our son was one of those people - not in Italy [France] but in Iraq - and he died."

The mix-up was even more surprising, given Biden himself visited the same cemetery only last month in an apparent rebuke to Trump.

The latest gaffe comes after the US president's "catastrophic" performance in his televised face-off with Trump last week, during which the 81-year-old appeared frail and confused, struggled to finish his sentences and mixed up words.

Biden's mental health has been a longstanding concern among American voters, according to regent polls, and many believe he is mentally and physically unfit for office.

A report released in May, by conservative news website the Daily Caller found that Biden has averaged more than one gaffe (1.3) per day in 2024. The analysis spanned 118 statements, speeches, and press encounters for which White House transcripts were issued and subsequently corrected by staff.

Meanwhile, videos of the US president stumbling, looking lost at press conferences, or misspeaking have been dismissed as "cheap fakes" by White House Press Secretary Karine Jean-Pierre.

The latest poll released by Morning Consult after the US president's disappointing debate performance suggested that 60% of voters believe Biden should "definitely" or "probably" be replaced as the Democratic presidential nominee.