Serbian midfielder Marko Grujic has become the first player to be signed by Liverpool under manager Jurgen Klopp, the Premier League club announced on Wednesday.

The 19-year-old Serbia Under-21 international has signed a four-year contract, but will return to selling club Red Star Belgrade for the remainder of the season before joining up with Liverpool in July.

Liverpool did not disclose the transfer fee, but they are believed to have paid around £5.1 million ($7.5 million, 6.9 million euros) to secure Grujic's services.

"I'm very excited and so proud to be here and a member of Liverpool Football Club. I can't wait to get started, play at Anfield and train at Melwood," Grujic told the Liverpool website.

"I was thinking about my progress in my next period and decided it was good for me to come here and try to be the best I can. I want to play in front of one of the loudest set of fans in Europe at Anfield.

"I also like the atmospheres at other stadiums. The crowds are very good. I like to play under pressure and that's why I've come here -- because it brings out the best in me."

Grujic made his debut for Red Star aged 17 in 2013 and has netted five goals in 21 games in their current league campaign.

As well as representing Serbia at Under-21 level, he was a member of the squad that triumphed at last year's Under-20 World Cup in New Zealand.

Klopp, who succeeded the sacked Brendan Rodgers in October, said: "We're very pleased because Marko is a big talent and we've seen him a lot of times.

"To describe him, I would say he's a tall boy, but quick and good at technical things. He can play passes and can dribble. But he is young, so he has to develop. He will do this, so everything is OK."

Klopp saw Liverpool win 1-0 at Stoke City in the first leg of their League Cup semi-final on Tuesday. They are currently eighth in the Premier League.