Russian President Vladimir Putin is coming to Seoul Tuesday for a two-day visit. His talks with President Park Geun-hye will cover a variety of issues, ranging from regional security to Russian-South Korean ties.

Among the key agenda items will undoubtedly be Korean participation in Russia’s development of Siberia, which is rich in natural gas and other resources ― an issue the two leaders broached when they met on the sidelines of the Group of 20 Summit in St. Petersburg two months ago. Park and Putin will need to have follow-up discussions.

One way to spur bilateral collaboration in Siberia is to extend the Trans-Siberian Railway to Busan. South Korea will be brought closer not only to Russia but also to the entire European continent if an envisioned Trans-Korean Railway is linked to the Trans-Siberian Railway ― the 9,259 km route spanning seven time zones from Moscow to Vladivostok.

Behind the push for the railway extension is a desire to cut shipping time and costs from South Korea to Europe by replacing maritime transportation with railway transportation. Moreover, a pipeline can be built along the railway to transport Siberian gas to South Korea.

President Park is quoted as saying that her administration has set its sights on Eurasian collaboration, with the railway extension proposed to facilitate freight transportation. But it is not Park alone that has been pushing for the idea of transporting freight from Busan to Europe via the Trans-Siberian Railway. Her predecessors proposed it, only to see their plans derailed as North Korea withheld its endorsement. In other words, it is North Korea that holds the key.

When they held the first inter-Korean summit in June 2000, former President Kim Dae-jung agreed with his counterpart, Kim Jong-il, to reconnect the railway that had run from Busan to Sinuiju in the North before being severed during the Korean War. But not many follow-up measures have been taken, with few lasting improvements in inter-Korean relations.

Yet, the initial stage of connecting the Trans-Siberian Railway to South Korea was completed when Hasan in Russia was reconnected to Rajin in North Korea by railway last month. Now a proposal to make use of the new rail link merits serious consideration by South Korea.

The idea is for a South Korean consortium to take over part of Russia’s 70 percent stake in a corporation managing the Hasan-Rajin project and transporting freight from Busan to Rajin by ship and from Rajin to European destinations by rail. This mode of transportation, experts say, will halve the delivery time, from four weeks to two, though the costs may remain the same.

But the ultimate question is how to convince North Korea to endorse the trans-Korean rail link for its own good. This problem cannot be addressed separately from overall inter-Korean relations, which now remain strained. This is the very reason why President Park should pursue with patience her professed goal of building trust with a wary North Korea. It goes without saying that President Putin’s assistance in this regard, if provided, should be highly appreciated.