The 63-year-old actor - best known for his roles as boxer Rocky Balboa in the `Rocky` movie series and troubled soldier John Rambo from the `Rambo` franchise - says his new movie `The Expendables` could be his last as the time is right for him to move on. He said: "I`m on borrowed time. At this age I hear the ticking clock and it`s as loud as the gong on Big Ben." However, he doesn`t want to leave the acting world completely and would like to showcase his talents behind the camera. Speaking at the Los Angeles Film Festival, where he received a special award for his successful career, Stallone said: "The ultimate ambition is to follow in Clint Eastwood`s footsteps and move on to directing films without me having to be in them. "I`m on borrowed time and know my longevity will be predicated on being able to make that move." In `The Expendables`, Stallone plays a gang leader of veteran mercenaries on a deadly mission and features cameo appearances from Arnold Schwarzenegger, Bruce Willis and Mickey Rourke. It is due for release internationally throughout August.