Russian President Vladimir Putin is considering running for a fourth Kremlin term in 2018, which would see him stay in power until 2024, the TASS news agency reports.

"Yes, the possibility exists of my standing as a candidate again. Whether or not it will happen, I don't know yet," Putin said in an interview.

He said although the constitution allows him to stand for another term, "that absolutely doesn't mean that I will take such a decision. I will look at the general context, my inner feelings, my mood."

"Is it really necessary to think about this now? 2014 isn't yet over and you're talking about 2018," Putin asked.

At the same time, he ruled out staying on as president forever.

"No, that's wrong for the country, it's harmful, and I don't need it," Putin said.

Putin is allowed to hold office for a maximum of two consecutive terms under the Russian constitution.

After completing his second consecutive term in office in 2008, Putin got round the constitutional limit by swapping roles with Dmitry Medvedev and serving as prime minister for one term, before returning to the presidency.

Now aged 62, Putin would turn 72 in 2024.

Soviet leaders Stalin and Leonid Brezhnev held onto power to a more advanced age, dying at 74 and 75 respectively while still in office.

Putin had last commented in 2013 on whether he would run for a fourth term, saying: "I do not rule it out."