Turkey launched a second drilling ship on Thursday which will conduct natural gas operations off the northeast coast of Cyprus for three months, a move which risks aggravating a conflict with Cyprus over jurisdiction rights for oil and gas exploration.
Turkey and the internationally recognised Cypriot government have overlapping claims in that part of the Mediterranean, an area thought to be rich in natural gas.
Energy Minister Fatih Donmez said at the launch of the vessel, Yavuz, it would operate in a borehole near Cyprus' Karpas peninsula, and reach a depth of 3,300 meters.
Turkey already has a ship offshore Cyprus, and Cyprus last week issued arrest warrants for its crew.
The dispute has escalated in the past month and also risks straining Ankara's relations with its western allies after the United States and European Union expressed concern at Turkey's drilling plans.
Ankara, which does not have diplomatic relations with Cyprus, claims that certain areas in Cyprus's offshore maritime zone, known as an EEZ, fall under the jurisdiction of Turkey or of Turkish Cypriots, who have their own breakaway state in the north of the island recognized only by Turkey.
Cyprus says that defining its EEZ is its sovereign right.
Donmez said unilateral agreements made between Cyprus and the regional countries that attempted to "steal" the rights of Turkey and Turkish Cypriots had "no legal validity".
"Turkey will continue its operations in its own continental shelf and in areas where the Turkish Republic of Northern Cyprus has licensed Turkiye Petrolleri without stopping," Donmez said, referring to Turkey's main oil exploration company.
"We are warning actors from outside the region that are forming cooperations with Cyprus: Do not chase illusions that will yield no results," he said.
Greece, which backs the Cypriot government, has called on the European Council to condemn Ankara's actions in the region.
Cyprus has also threatened to jeopardize European Union enlargement talks if the bloc does not take action against Ankara.
Cyprus was divided in 1974 after a Turkish invasion triggered by a brief Greek-inspired coup. Several peacemaking endeavours have failed and the discovery of offshore resources has increasingly complicated peace negotiations.
(Reporting by Can Sezer and Ezgi Erkoyun; Writing by Ali Kucukgocmen and Tuvan Gumrukcu; Editing by Daren Butler and Alexandra Hudson)