Growing demands for Joe Biden to step aside as presidential candidate after press conference gaffes

US President Joe Biden had a series of verbal slip-ups yesterday on the sidelines of the NATO summit in Washington DC, as the 81-year-old 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 scrutiny on him amid the fallout from his dismal debate performance against Republican candidate Donald Trump last month. At the press conference yesterday, Biden mistakenly referred to Ukrainian President Volodymyr Zelenskiy as "President Putin", drawing gasps from those in the room. But Biden immediately stepped back to the podium to correct himself. "Going to beat President Putin, President Zelenskiy. I am so focused on beating Putin," he said. In a separate press conference, Biden mixed up the name of his vice president Kamala Harris with his rival Trump when he responded to a question from Reuters about his confidence in Harris. Trump, who is 78, has also faced concerns about his age - but was convicted in May of falsifying records to cover up a potential sex scandal, making him the first ex-president convicted of a crime.