Vladimir Putin will have a “key role” in Russia for years as prime minister, new President Dmitry Medvedev declared Thursday, the Associated Press reports.

Putin was confirmed as prime minister by 392 of the 448 deputies at an extraordinary session of the lower house of parliament, the State Duma, just one day after Medvedev was inaugurated at a Kremlin ceremony. Medvedev took over the presidency after Vladimir Putin had spent eight years as president.

At Thursday’s vote confirming Putin as premier, his protégé Medvedev said, “I think no one has any doubt that our tandem, our cooperation, will only continue to strengthen,” according to the same source.

55-year-old Putin, a longtime KGB officer, served as premier for five months in 1999 under Boris Yeltsin, who stepped down on December 31 of that year and handed him the presidency. Putin was elected to his first term three months later.

President Medvedev told the Duma that Vladimir Putin had been instrumental in setting goals for Russia’s development and “as Cabinet chairman will play a key role in their realization”.

There is skepticism regarding the division of responsibility between Putin and Medvedev, despite their insistence that they have worked well together for 17 years. Western commentators say it is uncertain how much power Putin will actually hand over to his successor as president.

The change of power comes at a quite difficult time in East-West relations, as the U.S. is condemning Moscow’s support for separatist rebels inside neighboring Georgia, and Russia is angry over NATO’s promise to give membership to Georgia and Ukraine.