Putin proposes Dmitry Medvedev for PM: Kremlin

"Putin submitted Dmitry Medvedev's candidacy to receive the agreement of the State Duma to appoint him prime minister," the Kremlin said in a statement shortly after Putin was inaugurated for a fourth term.

Medvedev, now 52, served as president from 2008 to 2012 when Putin had served the maximum two consecutive terms permitted by the Russian constitution.

Putin then returned as president in 2012 while Medvedev became prime minister in a deal that the men said they had long agreed, disappointing those who had seen Medvedev as a more liberal figure and prompting mass street protests led by opposition politician Alexei Navalny.

Putin and Medvedev first met in their native city of Saint Petersburg where they were colleagues in the mayor's office in the 1990s.

Putin, 65, is now set to serve until 2024 and is already the longest-serving Russian leader since Joseph Stalin. He won March polls with more than 76 per cent of the vote.