US President Joe Biden on Thursday had a gaffe when he introduced Ukrainian President Volodymyr Zelenskyy at a NATO conference 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,” Biden said. “Ladies and gentlemen — President Putin. President Putin,” Biden said, before catching his mistake and correcting it. “He’s gonna beat President Putin, President Zelenskyy,” the President said, adding, “I’m so focused about beating Putin. We’ve got to worry about it.” Zelenskyy deftly handled the flubbed introduction and quipped, “I’m better” to which Biden replied, “You are a hell of a lot better.” The gaffe comes at an inopportune time for Biden, as he has been under constant scrutiny in the wake of his poor showing at the debate two weeks ago against former President Donald Trump. Biden has faced growing calls to withdraw from the presidential race after the debate. Most of those have come from House Democrats, with Sen. Peter Welch being the only Democratic senator to make the call, having done so on Wednesday. On Wednesday, Axios reported that Senate Majority Leader Chuck Schumer (D-NY) is privately signaling to donors that he's open to a Democratic presidential ticket that isn't led by Biden. Schumer later issued a statement in which he said, "As I have made clear repeatedly, publicly and privately, I support President Biden and remain committed to ensuring Donald Trump is defeated in November." Biden has so far rejected the growing chorus of calls to drop out. The President clarified last Friday that he is staying in the presidential race and has no plans to withdraw despite the debate. Speaking at a rally in Wisconsin, Biden said, “They’re trying to push me out of the race. Well let me say this as clearly as I can: I'm staying in the race. I'll beat Donald Trump again.” Related articles: Ex-Aide reveals Biden's mental condition during campaign Harris aides discussed, 'What happens if Biden dies in office' Former student denounces detention as ‘anti-Palestinian racism’ Trump ends Secret Service protection for Biden’s children On Monday, Biden again stressed his belief that he could defeat Trump in the November election, and cited his previous defeat of Trump in the 2020 race. “I beat him last time. I will beat him this time,” Biden told MSNBC .