Sunderland have completed the signing of the USA striker Jozy Altidore from the Dutch side AZ Alkmaar on a four-year deal for an undisclosed fee. The 23-year-old arrived on Wearside on Tuesday to complete a medical and he became the manager Paolo Di Canio's sixth signing of the summer. Altidore began his career in Major League Soccer with the New York Red Bulls before joining Villarreal in 2008. He spent time on loan at Xerez, Besiktas and Hull – scoring one league goal as the Tigers headed for relegation from the Premier League in the 2009-10 season. The striker agreed a permanent move to AZ in July 2011 and finished his first season in Holland with a haul of 22 goals in all competitions before adding 23 for the 2012-13 Eredivisie season, helping the club to a first KNVB Cup in 31 years.