Russian President Vladimir Putin (L) walks with First Deputy Prime Minister Dmitry Medvedev in the Kremlin in Moscow in this June 8, 2006 file picture. Putin on Monday backed the candidacy of Medvedev to become Russia's next president. Putin said he "completely and fully" supported a proposal by four political parties -- including United Russia, which won a December 2 parliamentary election -- to nominate Medvedev. [Agencies]