Scarlett Johansson is battling with her own self-confidence to take on the role of a bloodthirsty gladiatrix - because she isn't sure she "fits the mold" of a warrior woman.

The sexy actress has signed a deal to star in Amazon, the story of a female gladiator in 200 BC who takes on the might of an army after her homeland is destroyed.

But although the star has dealt with guns and fight scenes in her previous big screen adventures, she's apprehensive at the prospect of transforming into a tough-girl action star.

She says, "I think I'm supposed to be a gladiatrix. These film guys are crazy about gladiatrixes. But do I fit the mold? I'm a Danish/Jewish girl from New York.

"I've done weapons training. I've fired all kinds of guns; 9mm semi-automatics, machine guns, shotguns. I've jumped off a 60-foot building. I learnt to ride for The Horse Whisperer. But I've never done a full-on action role.

"I guess I'm still waiting for my Cirque du Soleil moment. It would be fun."

(This news article provided by World Entertainment News Network)