Natalie Portman says it was ''daunting'' to take on the leading role in 'Jackie'.

The 35-year-old actress plays former First Lady Jacqueline Kennedy in the new movie, which deals with the aftermath of the assassination of her husband, President John F. Kennedy, and Natalie admitted she was initially wary of signing up for the movie.

She told The Wrap: ''It did give me pause, because I know the family went through so much, and you don't ever want to add to anyone's suffering. I'm sure it's not pleasant to relive this for anyone who went through it, but at the same time, I think our approach is quite empathetic. I have great respect for the woman she was and what she did and her accomplishments, and I hope and believe it comes through.

''It was very daunting. I had never done a role before that was someone who people knew how she looked and talked and moved so specifically. It put the pressure on to be quite specific. But luckily [director] Pablo Larraín's approach was so all-encompassing and psychological that I felt that I was able and free to put imagination into it also.''

And Natalie is happy that the movie leaves an air of ''mystery'' around the late star.

She said: ''I have no idea what she was really like. I think that we can only say that this is a fictional presentation based on some conjecture - of course, conjecture that comes from a lot of research. But none of us know her. And I think that's some of the beauty of the film, that it leaves her a mystery.''