Billie Joe Armstrong is renouncing his US citizenship over the Roe v Wade ruling.
The Green Day frontman, 50, says he is planning to move to Britain in the wake of the Supreme Court's decision to reverse the landmark 1973 ruling, leaving terminations illegal for millions of women in America.
He made the announcement while performing a concert in London on Friday night, with fans sharing his declaration on Sunday night.
He said about his homeland: "There's too much f****** stupid in the world to go back to that miserable f******* excuse for a country.
"Oh, I'm not kidding, you're going to get a lot of me in the coming days."
He also called the justices responsible for overturning Roe v Wade "p*****".
Armstrong went on to yell at his gig at London Stadium, on the band's Hella Mega tour with Fall Out Boy and Weezer: "F*** the Supreme Court of America".
He then played Green Day's anti-war anthem 'American Idiot', the title track of the group's album of the same name from 2004.
The record was written as a response to then-US president George W Bush leading America to invade Iraq after 9/11.
Armstrong joins an ever-growing number of celebrities hitting out at the Roe v Wade reversal, including Jack White, Taylor Swift, Billie Eilish, Olivia Rodrigo and Lizzo.
The 1973 Roe v Wade battle centred around 'Jane Roe', a pseudonym for Norma McCorvey. She was a single mother pregnant for the third time who wanted an abortion, and sued the Dallas attorney general Henry Wade over a Texas law that made it a crime to terminate a pregnancy except in cases of rape or incest, or when the mother's life was in danger – arguing the law infringed on her constitutional rights.
Joe Biden blasted Supreme Court's reversal of the ruling as "un-American" in an address from the White House, adding it was a "sad day for the court and the country" and calling the move "wrong, extreme and out of touch".