Biden introduces Zelensky at NATO event [Video]

A defiant Joe Biden insisted Thursday that he will run for another term as US president and beat Donald Trump, as a string of verbal gaffes at a major summit threw a harsh new spotlight on his fitness.

In a high-stakes press conference at the end of the NATO summit in Washington, the 81-year-old acknowledged the need to “allay fears” among Democrats but said he was determined not to step aside.

His bid to portray himself as in command was undermined by introducing Ukraine’s President Volodymyr Zelensky as his Russian foe Vladimir Putin earlier in the day, and then referring to Vice President Kamala Harris as “Vice President Trump” at the news conference.

Biden’s candidacy has been in crisis since a disastrous debate performance against Trump two weeks ago renewed concerns around his age — and the rare solo press conference, lasting about an hour, was designed to show he still has what it …