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.

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.