The Hollywood legend, who founded the Sundance Film Festival, made the comments at a graduation ceremony at Maine's Colby College on Sunday.

"You're stepping into a world that's, well, pretty rough. It's pretty chaotic, pretty divisive," Redford, 78, said.

"You've got climate change, you've got debt, you've got wars, you've got political paralysis. It's kind of a grim story. But the story, I think, can be retold, and I really believe that you're the ones to do it."

The two-time Academy Award-winning actor, director and producer went on to say that he believed collaboration between people and in the management of natural resources would help the next generation to succeed.

"Don't be afraid to take a risk, don't be afraid of failure, be bold," he added.

Redford is the latest celebrity to speak at a US college graduation.

Last week, Robert De Niro, speaking at New York University's Tisch School of the Arts, took a slightly less nuanced approach to the role, telling those receiving diplomas that they were "f---ed".

"When it comes to the arts, passion should always trump common sense. Yeah, you're f---ed. The good news is, that's not a bad place to start," De Niro said.

"A new door is opening for you, a door to a lifetime of rejection. It's inevitable. It's what graduates call the real world."

Fellow actor Matthew McConaughey has also provided some words of wisdom for the Class of 2015.

McConaughey spoke to graduates at the University of Houston about why his character in 1990s cult classic Dazed and Confused should have had less screen time.

"It's just as important where we are not as it is where we are," he said.