Watts scared about playing Marilyn Monroe

London: Naomi Watts admits she is "very scared" about portraying Marilyn Monroe in a forthcoming movie biopic.

She is set to play the iconic screen siren in an adaptation of Andrew Dominik`s "Blonde".

"It`s a huge pressure. We all feel we know her. I`m very, very scared about that," contactmusic.com quoted her as saying.

Watts is not the only star to be portraying Marilyn in a movie about her life - Michelle Williams is also set to play her in "My Week With Marilyn".