Ukrainian President Petro Poroshenko has congratulated Ukrainians on Naftogaz Ukrainy's victory over Gazprom in the Arbitration Institute of the Stockholm Chamber of Commerce, presidential press secretary Svyatoslav Tsegolko has said.

"Today, a significant contribution has been made to the energy security of our state," Tsegolko wrote on his Facebook page on Friday, quoting Poroshenko as saying.

According to the press service of the head of state, at a meeting with Naftogaz Head Andriy Kobolev, Poroshenko noted the extraordinary importance of this decision to Ukraine's national security.

"I believe that this is a historic victory, because if there was a loss in this court, Ukraine would face a direct threat of default," the president said.

He said that now that Ukraine has shown that it is able to protect national security and defend state interests, Kyiv would have a tougher position in talks with its foreign partners regarding the future of the gas transportation system and Naftogaz Ukrainy.

"It is an important positive event. We received a final decision of the Stockholm tribunal on the gas purchase and sale contract of 2009. Naftogaz received a positive decision on all points," Kobolev said.

According to him, in accordance with the decision of the Arbitration Institute of the Stockholm Chamber of Commerce, the "take or pay" provision for more than $45 billion, "which is a consequence of the so-called contract of Mrs. Yulia Tymoshenko [former Ukrainian Prime Minister Yulia Tymoshenko]," has been fully cancelled.

According to Kobolev, the price of gas that Naftogaz bought in 2014-2015 was reduced by about 30%. The saving amounted to about 1.8 billion dollars.

He also said that the price for that contract was $485 per 1,000 cubic meters of natural gas, and now the price will not exceed $350.

"Accordingly, the saving will be very significant for both Naftogaz and the entire Ukrainian state," Kobolev said.

Poroshenko congratulated Koobolev, the legal team of Naftogaz, the Ukrainian government and the people "on the fact that Ukraine has learned to defend its interests by using European courts."

The parties also discussed the prospects for the arbitration court's decision on gas transit, after which it will be possible to talk about the final figures of the debt.

"Talks with Gazprom have always been held on New Year's eve. This company refused to sign any agreements, having not only Ukraine, but also the whole of Europe under its thumb," Poroshenko said.

Kobolev also said that about 15 billion cubic meters of natural gas had currently been pumped into Ukraine's gas storage facilities.