"The existing gas transport artery is a strategic Ukrainian asset," Yushchenko said today. "By law, the state has a monopoly over it and manages it, and everything related to modifying this model requires a very thorough and cautious approach."
His comments contrasted with remarks by Russian President Vladimir Putin on February 1 that Kyiv had offered to revive talks on the venture.
Russia's gas monopoly, Gazprom, has long sought to gain control over Ukraine's pipeline system.
About 80 percent of Russian gas destined for Europe is pumped through Ukraine.