750-metre long 'cable car' link between Russia and China across Amur River.
The Arctic was at the centre of world's attention in recent years, with the Nordic countries now on a steady, but a serious race for dominance in the region.
'The contract in current market parameters is absolutely unprecedented', Putin told investors at the annual Saint Petersburg International Economic Forum.
Chinese investment to Russia-much of it in Siberia-has risen 36% compared with last year, but Russian ambassador to Beijing wants to see a far bigger level.
More than 20 new deals on energy, investment and education are inked in Beijing.
Going by train all the way from Beijing (or even London) to New York could become a reality.
After months of speculation, parliament and President rubber-stamp deal that will see gas sent to China.
Four times weekly service from Moscow-Chita-Moscow started on 27 October.
33 hour journey between the capitals could be in place by 2020.