President Joe Biden, in his first TV interview since dropping out of the White House race, warned that Republican candidate Donald Trump was “a genuine danger to American security.”

“Mark my words, if he wins… this election, watch what happens,” Biden told CBS News in a pre-taped interview broadcast on Sunday.

“He’s a genuine danger to American security. Look, we’re at an inflection point in world history… and democracy is the key.”

Biden, 81, has kept a low profile since withdrawing after his flailing debate performance against Trump underlined fears about his age and mental abilities.

In the short TV interview, recorded in the White House last week, he appeared frail but cogent, again admitting he failed in the debate but stressing that health-wise he has “no serious problem.”

Explaining his exit, he said other Democratic Party politicians standing for re-election feared he would damage their chances — and added that his only priority was to stop Trump from returning to power.

“A number of my Democratic colleagues in the House and Senate thought that I was going to hurt them in the (election) races,” he said.

“A critical issue for me still is — not a joke — maintaining this democracy.

“I have an obligation to the country to do what is the most important thing we can do, and that is — we must, we must, we must defeat Trump.”