World's elite gathers for Davos 2014

Russia's Putin acting out of weakness: Soros

George Soros on US-Russia relations

The U.S. and Russia need to better understand each other because Russian President Vladimir Putin is becoming "more regressive at home and more aggressive abroad," billionaire investor and philanthropist George Soros told CNBC.

"Putin is acting out of weakness because he was quite popular, and then the switchover between him and [Dmitry] Medvedev really turned the Russian population against him," Soros said in an interview that aired Friday from Davos, Switzerland. His pointed words come as Russia deals with terrorist threats in advance of the Sochi Winter Olympics, which opens in two weeks.

Soros on crisis in Syria

Soros did say that Putin's intervention in the Syrian chemical weapons crisis has "paid off, but he can't really convert it into a real change in Russia's standing in the world without dealing with the humanitarian issue [in Syria]."

Syria's civil war has already killed at least 130,000 people, driven up to a third of the country's 22 million people from their homes, and made half dependent on aid, including hundreds of thousands cut off by fighting. Talks to end the 3-year-old war were scheduled to start Friday in Geneva.

"I think in many ways [Syrian President Bashar] Assad himself and the regime has committed such violations against humanitarian law that they can't really remain in power," Soros said.

—By CNBC's Matthew J. Belvedere. Follow him on Twitter @Matt_SquawkCNBC. Reuters contributed to this report.