Halo 4 director Frank O'Connor has said that work on Halo 5 has already begun, with the game likely to appear on the upcoming Xbox 720 console.
In an interview with The Seattle Times, O'Connor said that the 343i team had already begun work on "future development."
"We definitely have a lot of smart people inside the studio and outside the studio thinking about future technology and future development," O'Connor said.
"We've done as much prototyping and storytelling and the future arc of the universe as we have on technology. So we're definitely working on the future but in some ways it's technologically agnostic at this point."
However, O'Connor also said that he was surprised by the Xbox 360 and that there is more to be gotten out of it:
"One of the really exciting things for me, being in this business for 20 years, is seeing what they can get out of that hardware. Every single year you think we've tapped out and there's always more you can get out of it."
Halo 4 is due for release on 6 November and will see the return of Master Chief, the series main protagonist. Set on a distant alien world called Requiem, it sees players battling a new enemy force called the Forerunners.
It also features Spartan Ops, an episodic full-CG interactive mini-series.
An Xbox 360 exclusive, 343i has also confirmed that Halo 4 would not appear on PCs. Also speaking to the Seattle Times, studio head Bonnie Ross said there were no plans "at this point" to release Halo 4 on PC.
Details on the Xbox 720 remain scarce, although according to Tech Radar, it will launch in time for Christmas, 2013 and possibly be called Xbox Infinity.
The next generation of PlayStation console, tentatively called the PlayStation Orbis, has apparently already started shipping to developers, with full development kits expected to be finished in January.