Florence Pugh is like a ''little sister'' to Scarlett Johansson.

The 24-year-old actress stars opposite the Oscar-winning star in the upcoming Marvel movie 'Black Widow' and the pair quickly developed a close bond.

Scarlett said: ''I don't have a little sister. But with Florence, it feels to me like there's some elements of big sister little sister.''

Scarlett, 35, admires Florence's self-confidence and admitted the younger actress encouraged her to have faith in her own choices.

She said: ''I wish I was as confident as she is when I was her age.

''She's body confident and has a lot of self-respect.

''She reminded me - just by listening to her talk about relationships with friends, family or her partner - how important it is to have confidence in your beliefs and desires.''

Florence was also praised by her 'Little Women' director Greta Gerwick for the sense of sisterhood she brought to the set and encouraged in her co-stars.

She said of Florence: ''She instinctively knows how to be in a big family group. She was always the first one in the play-fight, the first one telling a joke, starting a giggle-fest, eating the prop cakes.

''She had that bubbling-over energy of sisterhood.''

The actress has admitted she put pressure on herself to get her performance in 'Black Widow' right.

She said: ''When I signed on to 'Black Widow', I knew that it was going to take a lot out of me. I remember thinking at the time: I didn't want to ever do one of those films if I wasn't mentally and physically prepared. It's got a massive fandom.

''I was aware that this wasn't something I could just roll on to, because it means too much to so many people. So when I said yes, I was aware that I wanted to really throw myself into it. I think you have a lot of opportunity in those films, and I think you have a lot of power in those films to be who you want the world to follow and respect.''