If Gazprom refuses to pay the Ukrainian state-owned energy company Naftogaz under a ruling by the Arbitration Institute of the Stockholm Chamber of Commerce, Ukraine is determined to recover the relevant sums, including through seizing the Russian gas company's assets abroad, Ukrainian President Petro Poroshenko said.

"Russia's statements that it will not pay Ukraine under the Stockholm arbitration ruling are a weak position. As they say, there is no use throwing punches after the fight is over. There are international conventions and there is an impeccable legal position of Ukraine," Poroshenko said on Twitter last Thursday, March 9.

"A team of lawyers is working at my instruction to recover the relevant sums. Therefore, if Gazprom doesn't pay the compensation, we will be seizing its assets," he said.

It had been reported earlier that a dispute between Gazprom and Naftogaz in the Arbitration Institute of the Stockholm Chamber of Commerce concluded at the end of February, with Gazprom ordered to pay Naftogaz $4.63 billion for undersupplying gas contracted for transit. Based upon the results of two arbitration disputes between the companies regarding export and transit of gas, the former being in favor of Gazprom, the net payment it has to make to Naftogaz now is $2.56 billion.

The companies' contracts for supply and transit of gas are in effect from 2009 through 2019.

Gazprom announced on March 6 that it had filed an appeal against the Stockholm arbitration court's ruling regarding gas delivery and would file another appeal regarding the ruling on gas transportation before the end of March 2018. Naftogaz said in commenting on this that an appeal may be lodged exclusively regarding procedural technicalities rather than the essence of the ruling itself.