Norwegian authorities have seized a Russian vessel in the Arctic archipelago of Svalbard at the request of Ukraine.

The seizure was ordered as part of Ukraine’s efforts to recover a $4.22 billion arbitration award against Russia over the seizure of Ukrainian energy assets following Russia’s 2014 annexation of Crimea.

The vessel, the Professor Molchanov, is operated by Russia’s state weather and environmental monitoring agency and is currently being held in the Svalbard settlement of Barentsburg.

Russian President Vladimir Putin condemned the seizure, calling it “state terrorism” and warning that such actions could complicate future peace negotiations, the AP has reported.

Russia has protested the decision and said it plans to appeal, while Norway maintains that the vessel cannot leave its current location as the legal dispute continues.