Renowned American investor Jim Rogers warned Thursday of a stark future for Japan if it does not take drastic measures to curb its massive debt and severe population decline.

"As far as I can see Japan doesn't have a good future," Rogers said at a news conference in Tokyo, warning that the compounding of problems could even lead to social unrest and capital flight from the world's third-largest economy.

These problems could be compounded by disarray in the global currency market in the "foreseeable future," caused by skyrocketing debt and little inclination to practice austerity by world governments, he said.