National joint-stock company Naftogaz Ukrainy has confirmed the fact of appealing Swiss courts seeking to the enforce the recovery of $2.6 billion debt from Russia's Gazprom due to the unwillingness of the Russian company to execute its legal liabilities prescribed in the award of the Arbitration Institute of the Stockholm Chamber of Commerce, the company's press service has reported.

The press service said that Swiss authorities have taken measures against Gazprom's assets on the territory of their country.

Despite the current court awards and the prepayment made by Naftogaz on time, Gazprom refused to resume deliveries of gas to Naftogaz Ukrainy on March 1, 2018, as agreed, and also did not pay $2.6 billion. However, the Russian monopolist began to challenge the arbitration award in Swedish courts, declaring unreasonable claims, and initiated a new arbitration, trying to cancel the results of the previous one. In accordance with international law, arbitral awards are enforceable in almost all countries. Gazprom's challenging these awards cannot stop their execution, Naftogaz said.