"Sly had invited me to be in Expendables 2 but I was too busy filming CZ12 and couldn't make a commitment to the film. But he did extend his invitation to the third movie, which I agreed on the condition that I will be appearing as more than just a minor role with a few scenes," he said.
Jackie, who also suggested that Stallone should make the third film more "buddy buddy", will be joining rumoured returning action men Jason Statham, Jet Li and Sly himself.
The 58-year-old also revealed that he is preparing for another Hollywood film, tentatively titled Skip Tracer, with his Rush Hour co-star Chris Tucker but he's concerned that it could be Rush Hour 4.
"The script is currently viewed by Chris Tucker," he said.
"Personally, I feel that if he were to pick it up, it would be better if we turned it into Rush Hour 4 but I do think that three movies for the franchise is a perfect ending. It would be better to start a new buddy movie with someone new."