Newcastle United signed teenage defender Kevin Mbabu from Swiss side Servette.
The 17-year-old, who is predominantly a central defender, has put pen to paper on a three-and-a-half-year deal after a successful trial and will go into the club's development squad.
The Switzerland Under-19 international told the club's official website, www.nufc.co.uk: "I am delighted to join Newcastle United.
"Today is a big day for me. I've always wanted to sign for a club in the Premier League and Newcastle is one of the biggest there is.
"I want to finish my development here with the reserves before one day training with the first team and hopefully breaking into the first team."