Monaco have completed the permanent transfer of Portuguese midfielder Bernardo Silva from Benfica for a fee of 15.75 million euros ($18.25m), the club announced on Wednesday.

Silva, 20, has been on loan with the Principality club since the start of the season and has impressed in the 15 games he has started.

"Bernardo Silva is one of the talented young players around whom Monaco plan to build the future," vice-president Vadim Vasilyev said on the club website.

"He has already demonstrated his potential to our supporters this season and it was important for us to keep hold of him."