Eva Green has ''balls'' in '300: Rise of an Empire'.

The 'Casino Royale' beauty plays feisty warrior Artemisia in the follow-up to 2007's hit movie '300', and has described her character - who helps lead Persian king Xerxes' army to war - as a ''strong woman''.

She said: ''She has some balls, that's for sure. It's my first action movie. Artemisia's like an Amazon. She's a very, very strong woman.''

'300: Rise of an Empire' sees Rodrigo Santoro reprise his role as the powerful Xerxes, while little-known filmmaker Noam Murro replaces '300' director Zack Snyder in the director's chair.

Green is set to play another fiery character in 'Sin City: A Dame to Kill For' and reveals she took up an intense gym regime to prepare for the part.

She explained to Total Film magazine: ''I had to work out like hell. I looked like G.I. Jane.''

'300: Rise of an Empire' is due for release in August, while 'Sin City: A Dame to Kill For' is set to hit the big screen later this year.