AceShowbiz - Matt Damon is feeling the pressure of playing tragic U.S. Senator Robert F. Kennedy in a forthcoming biopic, because the role comes with "a lot of responsibility". Damon is in talks to play the politician who was assassinated in 1968, just five years after his brother President John F. Kennedy was gunned down in Dallas, Texas.

The movie will be directed by Seabiscuit helmer Gary Ross, and based on Evan Thomas' biography of Kennedy, titled "His Life". Damon has confirmed he'll take the starring role if he likes the script, but admits he's intimidated by the prospect of playing Kennedy.

He says, "Well I don't know that I can (play him well). It's part of the challenge, but I'm pretty confident I could do it. It would be a lot of research and time put in. Where I come from, he's a pretty important person and it's a lot of responsibility ... the script comes in in a few weeks and hopefully (it's) a good script."

Kennedy has previously been portrayed on screen by Martin Sheen in 1974 TV movie "The Missiles of October", by Casey Affleck in "The Kennedys of Massachusetts", and more recently by Dave Fraunces in 2006's "Bobby".