With tension simmering over Turkey sending energy research vessels and a warship into Cyprus’ Exclusive Economic Zone (EEZ,) a deal Cyprus made with foreign companies for an underwater pipeline has Turkey saying it will defend the rights of Turkish-Cypriots.

That was in reference to a revised $9 billion contract Cyprus made with the U.S.-based Noble Energy, the Dalek Group of Israel and Royal Dutch Shell which Ankara said was a violation of the rights of Turkish-Cypriots unlawfully occupying the northern third of the island since a 1974 Turkish invasion.

The Turkish Foreign Ministry objected to the contract that covers the distribution of revenues from natural gas exploitation from the Cyprus’s Aphrodite field in the eastern Mediterranean and the transfer of natural gas by underwater pipeline to Egypt’s Idku liquefied natural gas (LNG) terminal, said the Turkish news site Ahval.

Turkey, the only country in the world that recognizes the occupied territory it seized, disputes the boundaries of the EEZ of Cyprus, a member of the European Union that Turkey wants to join even as it doesn’t recognize the legitimate government and bars Cypriot ships and planes.

Cyprus Energy Minister Giorgos Lakkotrypis, the island would earn more than $9 billion in gas revenues over 18 years as a result of the deal with the three energy companies and Turkish-Cypriots want to share in that.

“It is understood that the agreement does not make any reference to the Turkish Cypriots and that Turkish-Cypriots are not allotted any share from the revenues,” the ministry said. Cypriot President Nicos Anastasiades had agreed to share potentially lucrative revenues but talks to reunify the island broke down in July, 2017 at the Swiss resort of Crans-Montana when Turkish President Recep Tayyip Erdogan and Turkish-Cypriot leader Mustafa Akinci said they would never remove a 35,000-strong army and wanted the right to militarily intervene again.

They also said Anastasiades’ offer wasn’t enough and wanted Turkish-Cypriots to take part it the licensing operations of foreign companies, although US giant ExxonMobil has already started drilling and reported finding a major gas field.

Turkey insists that the occupied territory is a legal part of the island. “Therefore, Turkey will maintain its principled and resolute stance to protect the rights of the Turkish-Cypriots, as well as its own rights in the Eastern Mediterranean, and will not hesitate to take the necessary steps for this purpose,” the ministry said.

It wasn’t indicated whether that was a threat to use military force although Anastasiades said he fears Erdogan’s intention is to take control one way or another, either by invasion or taking control of the seas around the island.

The Aphrodite gas field is off the southern coast of Cyprus in block 12 of the country’s maritime EEZ but Turkey said it owns parts of blocks 1, 4, 6 and 7 of the Cyprus EEZ at the same time it refuses to recognize the United Nations’ Law of the Seas.

Turkey sent a drillship to waters well inside the Cyprus EEZ in early May, while Turkey’s energy minister said that a second drillship named would begin drilling off Cyprus by July.