Former long-term allies of Russian President Vladimir Putin are questioning his political course and warning of economic fallout 15 years after he first came to power.

Putin was first elected president on March 26, 2000, and has ruled Russia ever since, including a stint as a prime minister, which helped him to avoid presidential constitutional limits. His third presidential term expires in 2018, but Putin hasn't yet confirmed if he's going to run for a fourth term.

Alexei Kudrin, Russia's finance minister in 2000-2011 and a former deputy prime minister, said Tuesday that Putin's focus on foreign policy means that Russia won't return in the coming years to the economic growth that would suit a great power.

Kudrin was speaking at a round-table discussion on Putin's 15 years in power.