US President Joe Biden dismissed concerns about his age on Wednesday, claiming that he felt "good" about running for a second term when he is currently 80 years old while seeking a second term to take on the "danger" he believes former President Donald Trump poses to democracy in the United States.

"I feel good, I feel excited about the prospects" of a second term, said Biden, who will be 82 by the end of his term.

In a surprise declaration on Tuesday, US President Joe Biden confirmed that he will seek a second term at the White House in 2024, in a video made by his campaign team, which opens with scenes from the January 6 attack on the US Capitol by supporters of former President Donald Trump.

"When I ran for president four years ago, I said we're in a battle for the soul of America, and we still are," Biden said. "This is not a time to be complacent. That's why I'm running for re-election."

As of now, Biden will be running against big names like Trump and Florida Governor Ron DeSantis, and former South Carolina governor Nikki Haley. Trump leads all rivals in a prospective field of 12 Republican candidates, according to opinion polls.

Polls also show that Americans are unenthusiastic about Biden running again, with a majority citing his age as a main concern. 

At a press conference in the White House, Biden said "I respect" people who question his suitability for the grueling job.

However, he claimed that "people are going to find out, they are going to see a race and they are going to judge whether I have it or don't have it."

"I may not be the only one, but I know him well, and I know the danger he presents to our democracy and we've been down this road before," he said upon being asked if he could beat Trump again.

Biden undoubtedly has a number of issues that contribute to his low approval ratings, including his handling of the Ukraine crisis, the dwindling economy, the pandemic response, a border crisis, and low ratings for personal qualities such as leadership, crisis management, and mental sharpness.

Biden’s age is already posing a risk for the Democratic party, which is currently the minority in the House of Representatives as Republicans have taken over. 

A recent poll this month by Ipsos shows Biden’s approval ratings at merely 39% with major concern regarding his age since he would be 86 years old next year and ironically a decade higher than the average American male's life expectancy.

Biden, who does not drink alcohol and exercises five times a week, has been deemed "fit for duty" by doctors following a check-up in February and according to the White House, he is mentally sharp for the job.

His reelection announcement prompted the Deputy Chairman of the Security Council of the Russian Federation Dmitry Medvedev to suggest that the US military take precautionary measures to avert irreparable damage in the event the "desperate grandpa" gets re-elected.

On his Telegram channel, Medvedev wrote: "Biden has taken his decision. A desperate grandpa." He explained: "If I was in the place of the US military I would quickly produce a fake briefcase with fake nuclear codes in case he wins so as to avoid irreparable consequences."