KIEV, Sept. 8 - Russia's likely refusal to adjust gas contracts is a serious threat to normal Naftogaz Ukrayiny operations and, for that matter, to an uninterrupted transit of Russian gas across Ukraine, said Ukraine's presidential energy security advisor Bohdan Sokolovsky.

"Media reports claiming that the Russian president will stand firm over the terms, agreed upon on January 19 2009, can be interpreted as additional proof that the 2009 gas scenario was not accidental and could be used in Ukraine as an election gimmick," Sokolovsky said on Tuesday.