Borussia Dortmund midfielder Christian Pulisic has joined Chelsea but will be loaned back to the German club for the remainder of the season, the Bundesliga club have announced.
Chelsea will pay £58m for the United States international, who has scored three goals in all competitions so far this term.
Pulisic's contract with Dortmund was due to expire in 18 months.
"It was always Christian's dream to play in the Premier League," Dortmund's sporting director Michael Zorc told the club's official website.
"That certainly has to do with his American background and as a result we were unable to extend his contract. Because of this, we have decided to accept an extremely lucrative bid by Chelsea, given the low contract security."
Pulisic, 20, joined Dortmund as a youth player in 2015 and has made over 100 appearances for the club.