THE HAGUE, Netherlands-Romania called on the United Nation's highest court Tuesday to set a maritime border between it and Ukraine that will fairly divide an estimated 100 billion cubic meters of natural gas and oil reserves under the Black Sea.

Romania took the dispute to the International Court of Justice, commonly called the "World Court," after years of negotiations failed to draw a line acceptable to both Bucharest and Kiev.

Speaking at the start of oral hearings, Romania's representative accused Ukraine of unfairly distorting maritime border rules.

Bogdan Aurescu, director general of Romania's Foreign Affairs Ministry, said Ukraine has exploited its ownership of Serpents Island, a tiny rocky outcrop, to propose a more southerly line in its favor.

Aurescu said the island was illegally annexed by the Soviet Union and handed to Ukraine at its independence and should be ignored by the court when it sets a border.

Ukraine is due to respond next week.

The discovery of major oil and gas deposits in the mid-1990s prompted arguments over access to areas in the Black Sea.

Romania and Ukraine signed a treaty in 1997 agreeing to negotiate a border settlement, and not to exploit the oil in the disputed area in the meanwhile.

Aurescu told the court his country's counterproposal is drawn up based on accepted principles for setting maritime boundaries.

The maritime border reached the United Nation's highest judicial organ at a time of heightened tensions around the Black Sea following the war between Russia and Georgia. Those two countries face off at the court next week.

Georgia has accused Russia of ethnic cleansing in the breakaway districts of South Ossetia and Abkhazia since the early 1990s and sought the court's immediate intervention to safeguard civilians targeted by Russian and separatist forces.

The 15-judge tribunal is the U.N. judicial arm dealing with disputes between member states. Its findings are binding, although it has no power of enforcement.