South Korean rapper Psy, whose song Gangnam Style became an internet sensation, has apologised for taking part in anti-US protests several years ago.
He issued a statement after US media reported he had performed in concerts protesting against the US presence in South Korea and Iraq.
The singer said he would "forever be sorry" for any pain he had caused, reported BBC online.
Psy is due to perform at the annual Christmas in Washington TV special. US President Barack Obama and his family are expected to attend the concert.
Psy's hit song Gangnam Style is the most-watched video ever on YouTube, with more than 900 million views since it was uploaded in July.
However, at a concert in 2002 protesting against the US military presence in South Korea, the singer smashed a model of a US tank on stage.
At another concert in 2004, Psy performed a song that described killing "Yankees" who had tortured Iraqi prisoners and killing their families "slowly and painfully".