Australian heartthrob Liam Hemsworth has landed his biggest role yet in " The Hunger Games," playing Gale Hawthorne, the best friend and hunting partner of Katniss Everdeen in District 12 in the post-apocalyptic nation of Panem.

With the all the buzz surrounding the movie and devoted fans of the novel clamoring to see how their favorite characters are brought to life on the big screen, the 22-year-old actor admits he was so nervous to see how it turned out that he watched the movie alone for the first time.

"I requested to see it alone I think because there were so much expectations already and no one had seen the film, I really didn't want it to suck," Hemsworth said today on " Good Morning America." "Now that I've see it, I feel great. It's honestly one of the most powerful films I've seen."

" The Hunger Games" has become a teen pop culture phenomenon and is poised to take the box office by storm, with analysts predicting the movie will take in over $100 million during its opening weekend, possibly breaking the record for the best U.S. premiere in March.

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Hemsworth and his co-stars Jennifer Lawrence and Josh Hutcherson, who play District 12 tributes Katniss Everdeen and Peeta Mellark who are chosen to fight for their lives in the annual Hunger Games, have graced the covers of countless magazines and quickly shot to teen icon status.

"I have never promoted something quite as big as this," he said. "So it's been very exciting meeting everyone and seeing how passionate people are about it."

Watch "Good Morning America" all week to see stars Jennifer Lawrence live Wednesday and Josh Hutcherson live on Thursday.

The young cast got along swimmingly on the set, and Hemsworth said he had a special bonding experience with Hutcherson, who introduced him to a great American delicacy: the White Castle hamburger.

"I didn't even know White Castle existed and then we went to Kentucky where he's from and we had White Castle and thought it was a good idea to play basketball right after White Castle," he recalled. "We threw up a little bit together. It was a real bonding moment."

But to get into character, Hemsworth actually had to cut out the White Castle, and took some advice from his older brother, "Thor" actor Chris Hemsworth.

"My brother texted me about a month out before we started shooting. I guess he heard that I was eating too much and had gained some weight so he said, 'It's called Hunger Games, not Eating Games.' So I took that to heart, started training a lot and eating a lot less and lost quite a bit of weight," he said.

Hemsworth, who is dating singer and actress Miley Cyrus in real-life, also bonded with his co-star Jennifer Lawrence, who plays his best friend and soon-to-be love interest onscreen.

"She's amazing. One of the best actresses I've ever worked with. So talented," he said. "She's perfect for this role. The character she plays is extremely courageous and young and doing really extraordinary things at such a young age and she is that person."

"The Hunger Games" opens this Friday, March 23 in theaters nationwide. Stay tuned to "Good Morning America" all week to see stars Jennifer Lawrence live Wednesday and Josh Hutcherson live on Thursday.