U.S. President Joe Biden mistakenly called Vice President Kamala Harris "Vice President Trump" during a solo press conference in Washington on Thursday, Jul. 12, 2024 (local time).

The blunder occurred just hours after Biden accidentally introduced Ukraine's President Volodymyr Zelensky as "President Putin" at a NATO summit, Reuters and CNBC reported.

"I wouldn't have picked Vice President Trump to be vice president"

"Look, I wouldn't have picked Vice President Trump to be vice president [if] I think she's not qualified to be president," the 81-year-old President said, mixing up his second in command with his Republican rival, former President Donald Trump.

Reuters observed that Biden, the oldest U.S. President to hold the office, "coughed frequently" and "occasionally garbled" his speech at the press conference which lasted for almost an hour.

However, the news outlet observed that Biden gave comprehensive responses on matters such as the Israel-Gaza conflict and the need for Western countries to manufacture more armaments to counter Russia and China.

Best opportunity to prove he could hold his own

CNBC noted that the conference on Thursday was "the best opportunity" for Biden to prove that he could hold his own against difficult questions and "think on his feet in an unscripted environment".

The press conference, however, was not able to convince his fellow Democrats of that.

Four minutes after Biden walked off the stage, U.S. representative for Connecticut's 4th congressional district Jim Himes took to X (formerly Twitter) to call for Biden to quit the presidential race.

"The 2024 election will define the future of American democracy, and we must put forth the strongest candidate possible," said Himes.

"I no longer believe that it is Joe Biden."

Joe Biden’s record of public service is unrivaled. His accomplishments are immense. His legacy as a great president is secure.

He must not risk that legacy, those accomplishments and American democracy to soldier on in the face of the horrors promised by Donald Trump. pic.twitter.com/FMMrTK8pb8

— Jim Himes 🇺🇸🇺🇸🇺🇦🇺🇦 (@jahimes) July 12, 2024

"We're not going to win in November with this president": George Clooney

Just Wednesday, Jul. 10, 2024 (local time), Hollywood actor George Clooney published an opinion piece with the New York Times asking for Biden to withdraw from the presidential race.

Clooney is one of Biden's biggest advocates and a Democratic Party supporter. Just weeks before, he helped Biden raise US$30 million (S$40 million) for his re-election campaign.

"We are not going to win in November with this president. On top of that, we won’t win the House, and we’re going to lose the Senate," said Clooney.

Qualified to defeat Trump

At least 16 out of the 213 Democrats in the House and one out of 51 of the Senate's Democrats have publicly called for Biden to withdraw from the presidential race.

Biden however, insisted that he would be staying in the presidential race and that he was qualified to defeat Trump.

"The only thing age does is create a little bit of wisdom if you pay attention," said Biden.

Top image via The White House/YouTube