Russian President Vladimir Putin visited a Moscow hospital where the body of Mikhail Gorbachev is being kept on Thursday and paid tribute to the former Soviet leader.The Kremlin said that Putin's schedule wouldn't allow him to attend the funeral for Gorbachev on Saturday.Gorbachev, who died Tuesday, will be buried at Moscow's Novodevichy cemetery next to his wife Raisa after a farewell ceremony will be held at the Pillar Hall of the House of the Unions, a historic mansion near the Kremlin that has served as the venue for state funerals since Soviet times.