Olivia Williams praises 'Hanna' star Saoirse Ronan

Hanna star Olivia Williams has praised her co-star, and the film's lead actress, Saoirse Ronan.

Williams said she was pleasantly surprised by Ronan's maturity when the two met while filming the Joe Wright-directed thriller last year.

"When I first met her on set I was going, 'I wonder what the magic will be with her, what's the deal?'" Williams told the Press Association. "And then she just turned those [blue] eyes on me and that's why.

"She just has this incredible direct look and focus and speaks volumes about what's behind it.

"You expect a bit of a madam when you've got someone who was so astounding at such a young age in Atonement, and is carrying this film, and she just couldn't be further from that. She was delightful and enthusiastic and still so keen to learn."

Ronan confirmed recently that she was forced to turn down a role in Peter Jackson's The Hobbit due to scheduling conflicts.

The 17-year-old actress has since been cast opposite former Bond girl Gemma Arterton in Neil Jordan's Byzantium.

Watch Saoirse Ronan in the trailer for Hanna below: