South Korean President Moon Jae In said Thursday in Russia that he supports three-way cooperation with North Korea after peace is established on the Korean Peninsula and inter-Korean cooperation is in full swing.

Moon, in a speech to parliamentarians on the first day of his three-day state visit, said that as the two Koreas head toward an era of peace and cooperation, Russia's active support and cooperation are highly appreciated.

"Once a peace regime is established on the Korean Peninsula, inter-Korean economic cooperation will be accelerated and expanded to tripartite cooperation with Russia," he told the State Duma, or lower house of parliament, ahead of talks with President Vladimir Putin scheduled for Friday.

Moon cited railroads, gas and the electricity grid as the most promising sectors for cooperation among the three countries.

His remarks came a day after telling Russian media outlets in a joint interview, "If the railroad is connected across two Koreas and if it can connect to Russia's Siberian train system, it would enable logistics distribution from Korea to Europe by railroad."

In the interview, he also predicted that the supply of Russian natural gas and electricity to North Korea and to Japan would "help promote co-prosperity on the Eurasian continent," according to remarks made available by the presidential office.

[Korea Summit Press pool]

Moon told the Duma that when railway, energy and power cooperation between the three countries is achieved, it will be a "robust foundation for an economic community in Northeast Asia."

Also in his speech, he pitched his idea for a multilateral peace and security cooperation body in Northeast Asia.

Regarding his April 27 and May 26 summits with North Korean leader Kim Jong Un, Moon said they committed themselves to complete denuclearization of the Korean Peninsula and an end to hostile relations between the two Koreas.

Already amid the "historic transformation" taking place on Korean Peninsula, North Korea has demolished its nuclear and missile test sites, while South Korea and the United States have responded by easing military pressure on the North through suspension of large-scale joint exercises, he noted.