The second stage of the Nord Stream gas pipeline that major European gas companies have agreed to build jointly with Gazprom is not only a blow to the interests of Ukraine and Slovakia, but increases the EU's reliance on Russia, Naftogaz Ukrainy CEO Andriy Kobolev said.

"Abundant pipelines mean choice and choice is good, not for European consumers but for Russia. If these gas pipelines are built, Russia will decide where, to whom and on what political terms gas is supplied," a Naftogaz spokesman said, citing Kobolev's comments in Bratislava.

"Europe must make a decisive stand in defense of its interests and not allow construction of new routes controlled by Gazprom. The traditional route through Ukraine and Slovakia is a direct, high capacity, supply route to Europe that is not controlled by Gazprom," he said.

Six companies are participating in the Nord Stream-2 consortium: Gazprom, E.ON, BASF/Wintershall, OMV, Engie and Shell. The project stipulates construction of two lines of a pipeline with capacity to ship 55 billion cubic meters a year from Russia to German across the Baltic Sea.