Democratic presidential candidate Hillary Clinton said on Saturday the United States has to be "much smarter" about how it deals with Russian President Vladimir Putin.

"That's why we have to be much smarter in how we deal with Putin and how we deal with his ambitions," Clinton said at a campaign event. "He's not an easy man ... But I don't think there is any substitute other than constant engagement."

(Reporting by Amanda Becker; Writing by Eric Beech; Editing by Sandra Maler)