Chelsea have signed Borussia Dortmund forward and United States international Christian Pulisic for £58 million.
The 20-year-old joined Dortmund as a youth player in 2015 and will remain at the German club until the end of the season on loan.
Pulisic has scored nine goals in 23 games for the US.
It is the highest transfer fee for an American player, beating the 20m euros Wolfsburg paid for John Brooks in 2017.