U.S. President Joe Biden made another slip of the tongue by referring to North Korean leader Kim Jong Un as the President of South Korea. During a fundraising event for his campaign in California, Biden stated, "Former President Donald Trump is proud of the 'love letters' he sent to South Korean President Kim Jong Un." The 81-year-old Biden often makes errors in his public speeches. Republicans are using this to question the mental and physical capabilities of the U.S. president in the partisan struggle. At the end of February, Biden underwent routine medical exams, and White House Press Secretary Karine Jean-Pierre clarified that the exams did not include an assessment of the president's mental abilities.