Nicole Kidman had "massive trepidation" about playing Lucille Ball in 'Being the Ricardos'.

The 54-year-old actress has confessed that she was extremely nervous about playing the 'I Love Lucy' star in the new biopic and credited the support of director Aaron Sorkin for helping her take on the part.

Speaking at a screening of 'Being the Ricardos' in Los Angeles, Nicole recalled: "I had massive trepidation about a month prior, and Aaron had to get on the phone and send me emails saying, 'You've got this.'

"It was frightening but incredibly exciting."

The new Amazon Studios movie centres on a single production week of the 1950s sitcom 'I Love Lucy' and focuses on the relationship between Lucille and her co-star Desi Arnaz (Javier Bardem) – who played Lucy and Ricky Ricardo in the comedy respectively - and Nicole revealed that the project helped her get to know "the woman behind the lipstick".

The 'Bombshell' actress explained: "I fell in love with her as I was reading the script. I realised what she was doing (was) trailblazing for women."

Javier also revealed that he knew little about his character despite the popularity of 'I Love Lucy' in the actor's native Spain.

The 52-year-old star shared: "I was obsessed with him and his skills as a comedian, as a person, as a producer and a musician at that time while being a foreigner in this country."

Sorkin recreated an iconic 'I Love Lucy' moment in the film with Ball stomping on grapes during a winemaking scene and Nicole was determined to perform it to perfection.

She said: "It was my obsession to get it absolutely accurate. It was his obsession to have this human being portrayed – what's behind the creation of Lucy Ricardo and who is the woman behind this character?"