The AZ Alkmaar striker revealed on Friday that a deal had been done and that he would be signing for Paolo Di Canio's side.
The 23-year-old has already experienced life in the Premier League after spending a spell on loan with Hull City back in 2009/10, scoring one goal in 28 appearances.
However, his reputation has blossomed since then and the powerful player scored 31 goals for AZ in all competitions last season.
The USA forward's arrival is just the latest in a series of acquisitions by Di Canio as he looks to overhaul a squad he inherited from predecessor Martin O'Neill.
The Black Cats unveiled Bosman free signings Valentin Roberge, Cabral and Modibo Diakite last week having also added youngsters Duncan Watmore and David Moberg Karlsson to the mix, and the Italian has a series of other targets in his sights.