Justin Bieber Jaden Smith Duet Madison Square Garden Aug. 31

Bieber Fever sufferers in the Big Apple will be in for a treat when Justin Bieber’s sold-out US summer tour rolls into Manhattan’s Madison Square Garden next week.

Bieber has invited “Karate Kid” Jaden to perform their single “Never Say Never” at the Aug. 31 show, The New York Post’s PageSix Column has revealed.

“Special security arrangements are being made for Jaden, who will appear onstage, and his family, including Will, to be in the audience for the concert,” says a source.

Sean Kingston and Biebs’ mentor — R&B star Usher — are also expected to appear.