U.S. President Joe Biden had a series of verbal slip-ups on Thursday alongside the NATO summit in Washington, an unfortunate development for the 81-year-old as he tries to move past concerns that he is too old to run for re-election.

Verbal gaffes are not unusual in the long political career of Biden, who overcame a childhood stutter, but there is closer attention on him amid the fallout from his dismal debate performance against Republican candidate Donald Trump last month.

Trump, who is 78, and also has faced concerns about his age, frequently made false claims during the debate and often rambles during campaign speeches.

Below is a summary of Biden’s mistakes on Thursday.

BIDEN MISTAKENLY CALLS ZELENSKIY ‘PUTIN’
Biden mistakenly referred to Ukrainian President Volodymyr Zelenskiy as “President Putin”.

“And now I want to hand it over to the president of Ukraine, who has as much courage as he has determination, ladies and gentlemen, President Putin,” Biden said at the NATO summit, drawing gasps from those in the room.

“Going to beat President Putin, President Zelenskiy. I am so focused on beating Putin,” Biden said while correcting himself.

BIDEN MISTAKENLY REFERS TO HARRIS AS TRUMP
During a news conference on Thursday evening, Biden mixed up the name of his vice president, Kamala Harris, and his rival Trump.