Lily Collins has "laughed" at suggestions she and Kristen Stewart are rivals.

The 22-year-old actress - who takes on the role of Snow White in upcoming comedy fantasy movie Mirror, Mirror - explained even though the Twilight star will play the same part in Snow White and the Huntsman - the two films are "so different."

"We've laughed about the fact that people think we're rivals because to us they're so different. I think the advertising is kind of genius because both films are being shown in this different way because they are such different stories. I've seen the trailers, I'm very aware of the other one. We've always been aware of each other and I'm excited to see what Kristen does. I'm excited for her and vice versa."

Lily admitted acting alongside Julia Roberts - who plays the Evil Queen in Mirror, Mirror - was a difficult experience because she constantly wanted to "pinch" herself that she was working with her.

"If I could have shown on screen how I was genuinely feeling when she was being mean to me, it would have been me smiling and laughing the whole time. Because it was me pinching myself that it was actually happening. She is an amazing, incredible woman."