World hails 'one-of-a-kind' ex-Soviet leader Gorbachev

In this file photo taken on January 14, 1992 former Soviet President Mikhail Gorbachev (C) enters the institute which carries his name, the Gorbachev Foundation, in Moscow.

World leaders paid tribute to Mikhail Gorbachev, the last leader of the Soviet Union who died Tuesday in Moscow aged 91.

The man who played a major role in ending the Cold War was praised for being a "rare leader" who helped change the course of world history.