Ukraine’s Naftogaz said on Tuesday that a Dutch court had approved its petition to freeze Gazprom assets in the Netherlands as the Ukrainian company seeks to enforce the payment of the US$2.6 billion award it was handed by an arbitration court earlier this year over the payment dispute with the Russian gas giant, according to oilprice.com.

At the end of February, the Stockholm arbitration court ruled in favor of Naftogaz in the payment dispute with Gazprom, ordering the Russian company to pay Naftogaz US$2.56 billion for failing to supply Ukraine with the agreed amount of natural gas over a period of several years and also for failing to pay the full transit fees for the gas it did pump in that direction.

On May 29, Gazprom said that it had appealed the ruling of the Swedish arbitration court, and said that it is “asking for a complete reversal.”

The next day, Naftogaz said that it had initiated enforcement of the US$2.6 billion court award in Switzerland and the Swiss authorities had started taking measures to seize Gazprom assets in Switzerland.

Ukraine is seeking to seize Gazprom assets in Switzerland, the Netherlands, and the UK, Ukrainian President Petro Poroshenko was quoted as saying last week, and those assets could include shares of Nord Stream and Nord Stream 2 AG.

Referring to Gazprom’s assets in the Netherlands, the Ukrainian company said today that “A Dutch court approved the petitions; however, six out of seven of Gazprom’s Dutch subsidiaries have refused to cooperate with the bailiffs. This does not affect the validity of the attachments.”

Gazprom, for its part, said in a statement on Tuesday that it had not yet officially received documents regarding Naftogaz’s action in the Netherlands to enforce the court ruling. The Russian company said that it had not received any official notifications of last week’s start of enforcement proceedings in Switzerland either.