Ukraine and Russia do not associate use of the gas transport system and Ukraine's membership in the Customs Union, Russian Ambassador to Ukraine, Mikhail Zurabov, said at the conference "Results of the Ukrainian Election and Options for Russo-Ukrainian Partnership" in Kyiv on Friday.

"The issue of the gas transport system doesn't hinge on the Customs Union," he said.

However, the Russian diplomat said that "if certain decisions are reached, they would foresee a serious decrease in prices on Russian gas for Ukraine."

Russian President Vladimir Putin earlier said that Ukraine has made a strategic mistake error in rejecting Russia and its European partners renting Ukraine's gas transport system, forcing Russia to opt for building gas pipelines to Europe that bypass Ukraine. At the same time, Putin stressed that Russia is open for dialog with Ukraine regarding the renting of its gas transport system.