The United Nations’ highest court has started hearings on a Black Sea border dispute between Romania and Ukraine.

One hundred billion cubic meters of natural gas and oil reserves are at stake.

Romania currently imports 5.25 billion cubic metres of natural gas a year so the untapped reserves in the area could meet almost 20 years of import demand.

Deserted for many years, the island, which is less than a kilometre across, now has 100 inhabitants, including members of a scientific exhibition.

The status of the island may be decisive in the ruling, since according to the United Nations Convention on the Law of the Sea, rocks that cannot sustain human habitation have no impact on a state's exclusive economic zones. Even the recent flurry of activity is irrelevant, the Romanian government argues.

Romania will present its case to the International Court of Justice in The Hague from Tuesday. Ukraine will follow next week.

The dispute dates back to 1967 between Romania and the former Soviet Union.

In 1997, both Romania and Ukraine said they would not exploit the reserves in the disputed area.
But the two sides failed to reach an agreement on the Black Sea border. Romania took the case to the court in 2004.

International maritime law ordinarily grants countries a 200 kilometre exclusive economic zone beyond their shores. But this would be impossible in the case of the Black Sea, which is only 600 kilometre across at its widest.

The court will likely take months to reach a decision. The findings of the court are binding.