Before high-stakes press conference, Biden gets Ukraine president’s name wrong

Hours before a high-stakes press conference aimed at dispelling concerns about his cognitive health, President Joe Biden appeared to confuse the leaders of Ukraine and Russia.

“Ladies and gentlemen, President Putin,” Biden said as he introduced Ukrainian President Volodymyr Zelenskyy at a NATO event in Washington on Thursday.

After walking away from the podium, the president turned and corrected himself. “President Putin? He will defeat President Putin! President Zelenskyy.”

“I’m better [than Putin],” Zelenskyy joked as he shook Biden’s hand.

Follow live coverage and watch Biden’s press conference at NBCNews.com.

Biden has been the world’s leading defender of Ukraine through two years of bloody war to thwart an invasion by Russia led by President Vladimir Putin.

The gaffe comes as the embattled president doggedly tries to reassure the public and his own party that, after a disastrous debate performance, he has the mental and physical stamina to be commander in chief and defeat former President Donald Trump in November .

In the two weeks since the debate, Biden has seen several members of his own party call on him to drop out of the race. He insisted he will not step aside and remains fit for work.

At Biden’s last press conference in February, where the president angrily denounced a special counsel report that called it “significantly limited,” Biden referred to Egyptian President Abdel Fattah el-Sissi as the “president of Mexico.”