Barcelona have completed the signing of United States full-back Sergino Dest from Ajax Amsterdam for 21 million euros plus five more in variables, the Liga side said on Thursday.

Barca's statement added that Dest, 19, had agreed to sign a five-year contract with a release clause of 400 million euros.

Dest, who broke into Ajax's first team from their academy last season and has played three times for the U.S., will be officially presented on Friday.

The defender will compete with Sergi Roberto for a first team berth after Portugal right back Nelson Semedo left Barca for Wolverhampton Wanderers last week.