Ukraine has accused Russia of seeking to illegally seize control of the strategically important Sea of Azov and Kerch Strait, as hearings opened in a high-stakes arbitration case between Kyiv and Moscow.

The hearings at the Permanent Court of Arbitration (PCA) are the latest in a string of international legal cases involving Russia and Ukraine linked to Moscow’s 2014 annexation of Crimea and its 2022 full-scale invasion of Ukraine, even as fighting continues to rage on battlefields in Ukraine.

Ukrainian representative Anton Korynevych told a panel of arbitrators in The Hague: “Russia wants to take the Sea of Azov and Kerch Strait for itself, and so it has built a great gate at the entrance to keep international shipping out while allowing small Russian river vessels in.”

The gate he referred to is a bridge built by Russia across the Kerch Strait after the annexation of Crimea.

The case is being heard in the Netherlands
A final judgment could take years (AP)

The 3.5 billion dollar (£2.62 billion), 12-mile bridge linking the Black and Azov seas carries road and rail traffic on separate sections and is vital to sustaining Russia’s military operations in southern Ukraine.

“The bridge is unlawful and it must come down,” Mr Korynevych told the arbitration panel.

Ukraine filed the case in 2016, two years after Russia annexed Crimea. It accuses Moscow of subsequently breaching a United Nations maritime treaty by building the bridge, barring Ukrainian fishermen from waters they traditionally fished, damaging the environment and plundering underwater archaeological sites.

Kyiv is seeking unspecified compensation.

Russia insists the arbitration court does not have jurisdiction. It says that if its five judges decide they do have jurisdiction, the court should dismiss Ukraine’s claims.

“Ukraine’s accusations in this case are, of course, completely groundless and hopeless,” Russian representative Gennady Kuzmin told the panel.

He argued that the Sea of Azov and Kerch Strait constitute “internal waters” that are not covered by the United Nations Convention on the Law of the Sea, the treaty Ukraine alleges Russia is breaching.

After Monday’s two opening statements, the panel hearings will continue for days behind closed doors. A final ruling could take years.