Naftogaz Ukrainy deems the two claims it has filed against Gazprom with the Arbitration Institute of the Stockholm Chamber of Commerce to be founded, has no intention to withdraw those claims, and expects to win them both, Naftogaz Ukrainy Chief Commercial Officer Yuriy Vitrenko said.

"No one is going to withdraw the claims and end the absolutely founded legal action against Gazprom," Vitrenko said on Facebook on Wednesday evening.

The claim lodged by Naftogaz with the Arbitration Institute of the Stockholm Chamber of Commerce in regard to the gas sale-and-purchase contract has been declared founded, and the demands of the Ukrainian company have been met, he said.

"Our claim regarding transit is no less founded. We have won one action, and we are expecting our second claim to also be victorious," Vitrenko said.

The Russian Foreign Ministry said on Wednesday that "preserving gas transit via Ukraine would only be possible if Kyiv offers competitive tariffs and neutralizes the well-known transit risks, including by dropping all claims and withdrawing the absurd lawsuits against Gazprom."

The ministry also said that the Nord Stream 2 project concept did not stipulate reduction of the scope of Russian gas transit through the existent pipelines.

"We have no faith in those statements. Last time they also assured us that the startup of the Nord Stream 1 line would not lessen the scope of gas transit across Ukraine. They lied," Vitrenko said in comments on the Russian Foreign Ministry's statement.

In his words, Russia publicly said there would be no transit via Ukraine under any circumstances after the current contract expires.

As reported, the Antimonopoly Committee of Ukraine also has claims against Gazprom. The committee imposed a fine of UAH 85 billion on Gazprom in January 2016 for abusing its monopoly position on Ukraine's market of natural gas transit. The ruling was upheld by several Ukrainian courts. The fine has grown to UAH 172 billion (about $6.6 billion) with the penalty for the failure to pay the principal sum, and Ukraine started a procedure to enforce the fine's collection.