It appears that President Yoon is not a big fan of the U.S. Congress:
South Korea’s presidential office defended President Yoon Suk-yeol on Thursday after he was caught on video using foul language to apparently refer to U.S. lawmakers.
In the video, Yoon is seen talking with U.S. President Joe Biden at a fundraiser for fighting infectious diseases in New York on Wednesday. As he turns away to leave, he appears to tell his aides with vulgar language that it would be embarrassing for Biden if the National Assembly did not approve of something unspecified.
The clip led to speculation and criticism that Yoon was referring to Biden’s pledge to contribute another US$6 billion to the Global Fund to Fight AIDS, Tuberculosis and Malaria. His mention of the National Assembly was interpreted as a reference to U.S. Congress.
A senior presidential official said he did not pay attention to the remarks and did not remember them as he was following the president from behind.
“He wasn’t speaking publicly on the stage but in passing, and although I don’t know who recorded it and how, I actually think it should be verified,” the official told reporters in New York.
Yonhap
You can read more at the link, but this is just another self inflicted political wound that Yoon’s critics can now dwell on for a couple of news cycles. He is already dealing with another self inflicted wound by showing up too late to London to give condolences at Westminster Abbey prior to the funeral for Queen Elizabeth II.