Scarlett Johansson says Black Widow uses her size to her advantage.

The 29-year-old actress plays the popular Marvel comic book character - who is also known as Natasha Romanoff - in forthcoming 'Captain America: The Winter Solider', and insists her alter-ego's is quick on her feet, which helps her beat her opponent.

Talking at the film's press conference at London's Dorchester Hotel, she told BANG Showbiz: ''Part of the Widow's fighting style is she uses her size, what makes her charming, is she uses her size against her opponent and to her advantage. She's fighting these big dudes and she's quick thinking, and quick on her feet. Mouse is hard to catch!''

Johansson claimed actors must be ''sympathetic'' to their character and make them ''likeable'' to ensure audiences are satisfied.

She added: ''I think any character you play you have to be sympathetic towards because even if it's that's a villainous character, you always have to have a bit of likeability to you. I think this character has a certain unexpected humility to her, she has that soft underbelly, and I have that same soft underbelly!''