The 23-year-old completed his move to the Stadium of Light on a four-year deal after spending the past two years in the Eredivisie.
|9/2||Sunderland are 9/2 with Coral to be relegated
"I’m thrilled to be here and I’m looking forward to getting adjusted as quickly as possible," he told the club's official website.
“It’s a fantastic club, everyone here is so welcoming, I’m really excited about this season – it has everything here, all the combinations to be a big club so I’m really excited to be a part of it.
"I’m just going to give everything I can to the team, that’s the biggest thing to get the respect of your team-mates and when you do that I think everything will fall into place."
The United States international will now link up with the team who are currently in Italy as part of a pre-season camp, before taking part in the Barclays Asia Trophy later this month.