WASHINGTON — (AP) — President Joe Biden opened his highly anticipated press conference Thursday with a recitation of his NATO accomplishments during the summit this week as he faced growing calls to withdraw from the presidential race.

He forcefully declared he would stay in the race and would win amid mounting pressure for him to exit the 2024 presidential race.

Ahead of the solo press conference on Thursday evening, Biden mistakenly referred to Volodymyr Zelenskyy as “President Putin” to audible gasps in the room. He quickly returned to the microphone: “President Putin - he’s going to beat President Putin ... President Zelenskyy,” Biden said.

Then he said: “I’m so focused on beating Putin,” in an effort to explain the gaffe.

“I’m better” Zelenskyy replied. “You’re a hell of a lot better,” Biden said back.

He addressed poling data, his ability to run for re-election, his previous debate with former President and Republican nominee Donald Trump in Atlanta in June and many other topics.

“Today, Kyiv still stands and NATO stands stronger than it has ever been,” Biden said in stressing the alliance’s support for Ukraine.

Democrats are facing an intractable problem. Top donors, supporters and key lawmakers are doubtful of Biden’s abilities to carry on his reelection bid after his recent debate performance, but the hard-fighting 81-year-old president refuses to give up as he prepares to take on Trump in a rematch.

He mistakenly referred to Trump as “Vice President Trump,” and Trump responded by mocking him on the truth social media site.

“I’m not in this for my legacy, I’m in this to complete the job that I started,” Biden said. “I’m the most qualified to be president. I beat Trump before and I’ll beat him again.”

He responded to a question about his schedule and having events earlier in the day so he can go to bed earlier.

“My schedule has been full bore. So if I slow down and I can’t get the job done, that’s a sign that I shouldn’t be doing it. But there’s no indication of that yet — none. Where has Trump been? Riding around in his golf cart filling out his scorecard before he hit the ball? I just got to pace myself a little more.”

Polls conducted after the debate in June largely agreed that Democrats nationwide have doubts about Biden’s ability to lead the ticket in November.

“I have to finish this job because there is so much at stake,” Biden said. “I’ve taken three significant neurology exams. They say I’m in good shape. I’m tested every single day and my neurological capacities and the decisions I make. Every single day I’m surrounded by good doctors. If my neurologist tells me I need another exam, I’ll do it. I am not opposed if my doctors tell me I need another exam.”

__ Associated Press writers Michael Balsamo, Colleen Long, Mary Clare Jalonick, Kevin Freking, Farnoush Amiri and Linley Sanders contributed to this report.