Zoe Saldana thinks she ''should have never'' portrayed Nina Simone in 'Nina'.

The 42-year-old actress - who is of Dominican and Puerto Rican descent - darkened her skin and wore a prosthetic nose to play the legendary singer in the 2016 biopic and she has admitted she should have ''done everything in [her] power'' to push for someone else to be cast.

Speaking to 'Pose' creator Steven Canals on Instagram, she said: ''I should have never played Nina. I should have done everything in my power with the leverage that I had 10 years ago -- which was a different leverage, but it was leverage nonetheless.

''I should have tried everything in my power to cast a Black woman to play an exceptionally perfect Black woman.''

Zoe tearfully admitted she was ''so sorry'' for taking the role and said she felt Nina ''deserved better''.

She said: ''I thought back then that I had the permission because I was a Black woman, and I am.

''But it was Nina Simone. And Nina had a life, and she had a journey that should have been and should be honoured to the most specific detail.

''Because she was a specifically detailed individual. About her voice, her views, her music, her opinions and her art. And she was so honest. So she deserved better.''

The 'Avatar' star urged other people to ''step up'' and tell Nina's story in the right way.

She said: ''We've been appropriating ourselves with someone like Nina Simone for a very long time, and I just want her story to be told, and I want it to be right because she deserves it.

''And America deserves it. Because the Americans that inhabit today's America deserve her story to be told.

''I know better today, and I'm never going to do that again. Never. I'm learning. I'm still processing it. I've been processing it for 10 years, and I think it's a conversation that I wanna have.''

Director Cynthia Mort previously defended her casting choice for the movie and insisted Zoe had been chosen for her acting skills.

She said: ''Certainly I would not have cast Zoe if I felt she was wrong for the role in a million years.

''Zoe's amazing. She's amazing in the movie. She gave her all. She's honest, she's courageous, she's fierce.''