SAINT PETERSBURG, Russia (Yonhap) -- South Korean officials on Wednesday downplayed the significance of a roadmap it had agreed with Russia to build a massive gas pipeline linking the two countries via North Korea, saying the project still has a long way to go.

On Tuesday, a senior Russian official said the two countries hope to start construction of the transnational gas pipeline in 2013 and transport Siberian gas through the connection in 2017.

The timeline was part of a memorandum of understanding South Korea's state-run gas firm Korea Gas Corp. signed in September with its Russian counterpart Gazprom on the project, said Nikolai Dubik, chief of Gazprom's legal department.

On Wednesday, South Korean officials downplayed the plan's significance, saying it is not legally binding and little more than wishful hopes for now. They stressed the two sides have not made any progress since September, and that any meaningful progress can come only after Russia and North Korea agree on pipeline transit fees.

"There has been no progress since the MOU in September," a government official said on condition of anonymity. "Russia has not yet made any commercial proposals to us, such as gas prices or terms of construction. Once proposals are made, we have to hold negotiations."

The ambitious project, which has been discussed for about 20 years but never materialized due in part to security tensions, gained momentum after North Korean leader Kim Jong-il expressed his willingness to permit the envisioned pipeline to go through the nation during summit talks with Medvedev in August.

South Korean President Lee Myung-bak and Russian President Dmitry Medvedev were expected to discuss the project during summit talks in Russia's second-largest city of Saint Petersburg Wednesday, along with efforts to end Pyongyang's nuclear ambitions.

"I doubt today's summit will produce any specific results (about the pipeline)," the government official said.

The project has drawn keen media attention because it could help reduce tensions on the divided peninsula. Lee has also said that the project is workable as it would benefit all parties involved.

But in an interview with the French newspaper Le Figaro published Tuesday, Lee also said there is a long way to go before the project comes to fruition.

"There will be a point in time where the South, the North and Russia hold three-way discussions," Lee said in the interview. "But before reaching that stage, a lot of conditions must be fulfilled. Discussions on the gas pipeline project could proceed swiftly, or not. It is difficult to predict for now."