Mikhail Gorbachev, who ended the Cold War without bloodshed but failed to prevent the collapse of the Soviet Union, died on Tuesday at the age of 91.
He was suffering from a kidney ailment, but the cause of his death is not yet known, Reuters reported.
“Mikhail Gorbachev passed away tonight after a serious and protracted disease,” said Russia’s Central Clinical Hospital.
Putin expressed “his deepest condolences”, Kremlin spokesman Dmitry Peskov told Interfax. “Tomorrow he will send a telegram of condolences to his family and friends,” he said.
He will be buried in Moscow’s Novodevichy Cemetery next to his wife Raisa, who died in 1999.
Gorbachev who had resigned from his post as president on December 25, 1991, was awarded the Nobel Peace Prize in 1990 for the “leading role he played in the radical changes in East-West relations”.
United Nations Secretary-General António Guterres wrote on Twitter that Gorbachev was a “one-of-a-kind statesman who changed the course of history”.
“The world has lost a towering global leader, committed multilateralist, and tireless advocate for peace,” Guterres added. “I’m deeply saddened by his passing.”