An international arbitration panel in the Netherlands has begun preliminary hearings of Kyiv's complaints against Moscow’s alleged violations of its rights to coastal waters around Ukraine's Crimea region, which Russia seized in 2014.
Russian representatives on June 10 urged the Permanent Court of Arbitration (PCA) in The Hague to throw out the case, arguing that the panel "does not have the jurisdiction to determine Ukraine's claims."
Ukraine will present its arguments on June 11. The second stage of the debate will take place on June 13-14.
Ukraine filed the case at the PCA in September 2016, accusing Russia of violating the UN Convention on the Law of the Sea concerning its coastal rights in the Black Sea, the Sea of Azov, and the Kerch Strait.
Kyiv asked the arbitration tribunal to "enforce its maritime rights by ordering the Russian Federation to cease its internationally wrongful actions in the relevant waters."
On June 10, the head of Russia's legal team, Dmitry Lobach, objected to Ukraine’s move, claiming that the case falls outside the scope of the Convention on the Law of the Sea.
"It is clear that the thrust of Ukraine's claims is over Russia's sovereignty over Crimea and the maritime zones," Lobach told the PCA. "Despite the high regard with which Russia regards this tribunal, it cannot determine which state is sovereign over Crimea."
It is not clear when the PCA, the world's oldest institution for the arbitration and resolution of disputes involving states, will issue a decision on jurisdiction.
Kyiv has filed a series of legal complaints against Moscow over its seizure of the Crimean Peninsula in March 2014 and its support for separatists in eastern Ukraine in a conflict that has killed some 13,000 people.
Ukraine and its Western backers have accused Russia of illegally restricting the passage of Ukrainian ships through the Kerch Strait, which is the sole passage from the Black Sea to the Sea of Azov.
In November, Russia seized three Ukrainian naval vessels and captured 24 Ukrainian seamen near the Kerch Strait, prompting international condemnation.
In Hamburg, the International Tribunal for the Law of the Sea last month ruled that Russia must "immediately" release the Ukrainian sailors and vessels.
The Kremlin dismissed the ruling, saying Moscow would continue to "consistently defend its point of view."
Russia Argues Against Ukraine's Black Sea Case Before Arbitration Panel