Manchester United have completed the signing of forward Anthony Martial from Monaco.
The 19-year-old has signed a four-year contract at Old Trafford after United made their surprise move for him.
The Premier League side paid Monaco a fee of £36 million for his services, sources said, making Martial the most expensive teenager in the sport's history.
Martial, who had been called up to the France squad for the first time, left their training base at Clairefontaine on Monday to undergo a medical at Old Trafford and finalise his move.
#mufc is pleased to announce French forward @AnthonyMartial has completed his transfer from Monaco. #WelcomeMartial pic.twitter.com/Eohl6tMOOz
- Manchester United (@ManUtd) September 1, 2015
Martial told United's official website: "I am so excited to be joining Manchester United. I have enjoyed my time at AS Monaco and I would like to thank them and the fans for everything they have done for me.
"I have always wanted to play in the Premier League and to join the biggest club in the world is what every young footballer dreams of. I am looking forward to meeting my new teammates and working with Louis van Gaal who has achieved so much in his career."
Martial is a player United manager Van Gaal had scouted several times over the past year and the former Premier League champions acted quickly after Monaco's elimination from the Champions League meant a deal became possible.
But Van Gaal said: "Anthony is a naturally talented, young, multi-functional forward with great potential. We have been watching him for a while now and he has developed immensely during his time at AS Monaco.
"I am delighted he has joined Manchester United as I believe this is the right club for him to continue his development as a young player. He has all the attributes to become a top football player; however we need to give him time to adjust to his new environment and the rhythm of the Premier League."
United have only twice paid more for a player, buying Di Maria from Real Madrid for £59.7m and Juan Mata from Chelsea for £37.1m, both last year.
The former Lyon striker, who joined Monaco for €5m in 2013, has scored 15 goals in 72 games in his senior career.
He arrives after four forwards left Old Trafford this summer, with United opting not buy Radamel Falcao after an unsuccessful loan spell and selling Robin van Persie to Fenerbahce.
On Monday, they sold Javier Hernandez to Bayer Leverkusen and allowed Adnan Januzaj to join Borussia Dortmund on a season-long loan.
Martial's France teammate Morgan Schneiderlin compared the striker to France's record goalscorer by saying he is "a little like Thierry Henry."
He has become United's sixth summer signing, after Memphis Depay, Matteo Darmian, Bastian Schweinsteiger, Morgan Schneiderlin and Sergio Romero, taking their spending past £100m.