The Ghana youngster has been likened to fellow countryman Michael Essien and admits that he looks up to the Chelsea midfielder.
He also reveals that Inter will have the final say on any move.
"I am flattered by the interest of Sunderland," Duncan told reporters.
"I know the scout of Sunderland has been watching me. To be honest though, nothing has been done, and Inter will have a big say if I leave or not.
"Fans compare me to Essien and if I can have half of his career I will be very happy."
Sunderland have already made four signings so far this summer.