Manchester United have announced the signing of Argentina goalkeeper Sergio Romero.

The 28-year-old, who helped the Albiceleste reach the World Cup final last summer, joins the Red Devils on a three-year deal from Sampdoria.

The South American, who is expected to replace Victor Valdes, says that the move is a "dream come true" for him.

"I am absolutely delighted to join Manchester United," he told the club's official website.

"To play for the biggest club in the world is a dream come true for me. Louis van Gaal is a fantastic manager and I cannot wait to get started on this new and exciting challenge in my career."

Van Gaal, who previously coached Romero at AZ Alkmaar, added: "Sergio is a very talented goalkeeper. He was a young keeper during my time at AZ Alkmaar and I am delighted he is joining Manchester United.

"He had a fantastic World Cup last summer in Brazil, although that is something I have put to the back of my mind!

"He will be a great addition to the team and I am looking forward to working with him once again."

Romero will compete with David de Gea - who has been linked with a move to Real Madrid - for the number one shirt during the 2015-16 season.