REUTERS Fonda couldn't resist playing Nancy Reagan

Jane Fonda just couldn’t say no to a Nancy Reagan role.

“The idea that I could play Nancy Reagan was just too much to resist," the actress says in a new clip promoting “The Butler." "I thought it would be fun to play her."

Acknowledging their political differences, Fonda adds, “I know people say, ‘Oh my gosh, Jane Fonda is playing Nancy Reagan.’ But I don’t think that whatever difference there might be in our politics really matters. As an actor, I approach her as a human being.”

Plus, Fonda says, “I happen to know that she’s not unhappy that I’m playing her.”

Watch Fonda as the first lady in a preview of "The Butler" below. The movie, which follows the career of a long-serving White House butler, hits the big screen on Aug. 16.