MOSCOW, March 12 (Xinhua) -- Russian President Vladimir Putin said the biggest achievement during his tenure is economic development with the scale of the country's economy having almost doubled.

"Our biggest achievement is that our economy has changed radically," said Putin in an interview with the American broadcaster NBC that aired over the weekend.

Putin said the number of people living below the poverty line has decreased by half, though the number still living in poverty remains high.

"We must remove the gap between people with very high and very low incomes," he added.

By noting the country's gold and currency reserves are growing, Putin said this provides an opportunity to "take the next step" towards enhancing labor efficiency, attracting investment and changing the structure of the Russian economy.