US rapper ASAP Rocky is due to go on trial in Sweden, accused of assaulting a 19-year-old in Stockholm.
Donald Trump has publicly called for his release on Twitter and has also spoken to the Swedish prime minister about the case.
But who is ASAP Rocky, and why has the US president got involved?
Presented by Radio 1 Newsbeat reporter Nesta McGregor
Who is rapper ASAP Rocky on trial in Sweden?