Liverpool have signed Red Star Belgrade midfielder Marko Grujic for £5.1m on a four-year contract.

The 19-year-old will return to the Serbian club on loan until the end of the season and join up with the Premier League side on 1 July.

"I was thinking about my progress in my next period and decided it was good for me to come to Liverpool and try to be the best I can," he said.

"I want to play in front of one of the loudest set of fans in Europe at Anfield."