BARCELONA (Reuters) -Barcelona have completed the signing of United States full-back Sergino Dest from Ajax Amsterdam for €21 million (S$33.6 million) plus €5 million more in variables, the Liga side said on Thursday (Oct 1).

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

A club statement read: "Sergino combines many excellent qualities needed in a full back: attacking when called for, solid defensively, unruffled in possession and creative with it.

"The defender has the ability to take players on and his pace is a virtue going forward and defending. Those qualities will be on display from now on in a Barca shirt, a challenge for a fearless young full-back."

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

The defender, who turned down a move to suitors Bayern Munich, will compete with Sergi Roberto for a first-team berth after Portugal right-back Nelson Semedo left Barca for Wolverhampton Wanderers last week.