Robert Pattinson has described Kristen Stewart's "excitement" for her role in the latest Twilight movie.

The actor revealed how much his co-star and on-off girlfriend is looking forward to the final instalment of the hit franchise.

Robert also discussed how Kristen handled her character Bella's transformation.

"She was really excited about being a vampire," Robert revealed to MTV Australia. "Everybody else who'd been pretty consistently in the movies, they'd obviously been playing a vampire like every day for ages. And so it's funny seeing someone suddenly come into it and try and figure out their own version of the physicality and the mentality of it. But her character has a different thing, because she's supposed to find it really easy. It's supposed to be a natural progression for her to become a vampire, it's supposed to be simple. So I guess it was kind of different."

The 26-year-old British actor is in Australia to promote the final instalment of the hugely popular franchise. He reflected on his memories of making the hit vampire movie series.

"There's been a few. I mean, going to Brazil on this one was pretty fun, it was pretty crazy. I crashed a speedboat which was pretty exciting! Yeah tons. Tons from the first movie, it was just so different being the first one. I mean we used to travel to set, the entire cast, in a minibus," Robert continued. "It was so entirely the opposite of what the last one ended up being - like being in helicopters and stuff."