The move comes amid hope of large-scale investment from Seoul into Siberia.
Officials from Russia and North Korea say the long-waited train connection is now almost ready.
The distance between capital city Moscow and key Siberian cities could shrink in plan envisaged by the Kremlin leader.
One estimate is half a million new jobs stemming from improvements to the Baikal-Amur Mainline link amid hopes of foreign investment.
The Russian government is to give priority to Siberia and the Far East as it puts modernisation on fast-forward, insists Dmitry Medvedev.
Proposals have been made for high speed trains to run on two routes between Omsk and Novosibirsk, and Novosibirsk and Krasnoyarsk.
What I wasn't expecting was just how beautiful everything looked under the sparkling white blanket of snow.
The flame warms Siberia and even takes a dip in Lake Baikal en route to the Sochi Winter Games.
It should be called the 'Pacific region', he suggests.