Liam Hemsworth "doesn't even know" how his girlfriend Miley Cyrus feels about his work.

The 22-year-old Australian actor stars in The Hunger Games, an upcoming film adaptation based on the first book of the eponymous fictional young-adult sci-fi action trilogy written by author Suzanne Collins.

Liam is incredibly impressed by the series and hopes that Miley has similar sentiments.

"Well she didn't know about [the books] until I got attached to [the film]," Liam told E! Online. "And then she read the book. I hope she liked it. I don't even know. She better watch it!"

Liam is elated about how The Hunger Games film adaptation came out. He hopes that movie executives will be compelled to make films of all the novel instalments.

"If it does as well as everyone's expecting it to do, then I imagine they'll go ahead," Liam explained. "I love the books. The books are great, so if we get to shoot all three films I'll be really happy."

Liam is excited about all of his upcoming projects. Filming Expendables 2 opposite action legends Arnold Schwarzenegger, Bruce Willis and Sylvester Stallone has been a dream come true for the fledgling actor.

"It was pretty amazing," Liam gushed. "I grew up watching all those guys and I remember just sitting on set the first day and I had this scene where I had a bunch of dialogue and it was just my character talking in front of all these guys... I was like, 'Oh my god. I'm sitting with some of my biggest action idols that I'd grown up watching and now I'm on set with these guys.' It was a real pinch-yourself moment."

The Hunger Games will be released in March and Expendables 2 will reach theatres this summer.