Jason Clarke said it was a "bummer" a sequel to 'Terminator Genisys' didn't get made.
The 48-year-old actor starred as John Connor in the 2015 movie by Alan Taylor, and although the movie - which was the fifth instalment in the 'Terminator' franchise - was panned by critics, Clarke revealed there was an idea for a sequel.
He told Digital Spy: "They had an idea. What I remember was that the second one was going to be about John's journey after he was taken by Skynet... like going down to what he became; half-machine, half-man.
"That's where the second one was going to start, and that's about all I knew. It's such a bummer we didn't get to do that."
The film follows soldier Kyle Reese (Jai Courtney) in the war against Skynet who is sent from the year 2029 to 1984 by John Connor (Clarke) to protect Connor's mother Sarah (Emilia Clarke).
When he arrives in the past, he discovers that the timeline has been altered and Sarah has been raised by a reprogrammed Terminator (Arnold Schwarzenegger).
Now, a much-anticipated reboot is in the works and is being directed by Tim Miller, but for the first time since 1991's 'Terminator: Judgment Day', James Cameron is also involved with the film series.
Cameron was at the helm for the original 1984 movie and sequel 'Terminator 2: Judgment Day', but was not involved in 2003's 'Terminator 3: Rise of the Machines', 2009's 'Terminator Salvation' or 'Terminator Genisys'.
Plot details are being kept under wraps but Miller and Cameron are reportedly treating the film as a direct sequel to 'T2: Judgment Day'.
In the original movie, Schwarzenegger played the villain a T-800 killer cyborg - alongside Linda Hamilton as Sarah Connor, but in the sequel his character was the hero.
Hamilton is also on board to be reprising her role in the upcoming movie.