Felicity Jones took 25 takes to perfect the line 'May the force be with us'' in 'Rouge One: A Star Wars Story'.

The 33-year-old actress stars as Jyn Erso in the upcoming spin-off movie, and was ''nervous'' about getting the iconic catchphrase in the sci-fi movie right.

Speaking during a Facebook Live interview with MTV, she shared: ''It's a big line but I don't wanna overdo it, I don't want this to be hammy. So I'm just trying to say it casually, you know, just throwing it out there.

''There are always certain lines and certain scenes that you have in your head that, before you go in shooting, you feel just a little nervous about. You have this calendar in your head that you're dreading.

''I must have done about 25 takes of that line. And it was quite a big set-up because it was all of us coming in and walking up and she says the line.

''Each turnaround was about 15 minutes so you have a lot of time to think. It's just one of those magical moments everyone wants to get right.''

Getting a part in 'Rogue One' - which also stars Diego Luna, Mads Mikkelsen and Forest Whitaker - has been a dream for the 'Inferno' star, who previously said she was a fan of 'Star Wars' before she joined the franchise.

Felicity can ''remember watching'' George Lucas' original trilogy with her family when she was younger.

She said: ''I remember watching when I was a little girl. I'd watch at my cousin's house with my older brother, and for some reason we'd be really close to the TV watching it. We would watch it on VHS. I just remember the opening titles going up the screen.''

And it wasn't just the ties to the 'Star Wars' mythical universe that drew Felicity to the role, as she also spoke out about how Rebel Alliance soldier Jyn's ''spirit'' made her a ''fantastic character'' to portray.

She added: ''It was the opportunity to play a kick-a** girl. She's a real live wire. She's got real spirit, and it was a just a fantastic character to make.''