Ubisoft's long-delayed Rainbow Six: Patriots has been officially cancelled, with Siege its replacement.

"It's not in development any more," Rainbow Six brand director Alexandre Remy told Polygon. "The main decision was some months after Patriots was announced in 2011 that was the first moment we knew the first generation of new consoles were coming. So obviously at that moment and for a franchise such as Rainbow we needed to decide if we could make something for next-gen and we were already pretty advanced in the development of Patriots.

"It would require doing a lot of extra things."

Remy goes on to note the reasons behind the change. "It was a strategic decision to make that happen," he adds. "It's hard to imagine a Rainbow Six game that doesn't use the latest technology. We had to decide do we keep working on something that might be a bit late in the cycle or do we actually take that opportunity of next-gen?"

Rainbow Six: Siege continued Ubisoft's tradition of closing its E3 press conference with a new IP announcement, and the gameplay demo certainly impressed viewers with its high intensity and incredible destruction thanks to the Realblast engine.

Siege is set for a 2015 launch on PlayStation 4, Xbox One and PC.