A second Turkish ship planning to drill for oil and gas off Cyprus arrived off the Mediterranean island's northeastern coast on Monday, triggering a strong protest from Nicosia of an infringement by Turkey of its sovereign rights.
Last month, European Union leaders warned Turkey to end its gas drilling in waters around the island or face action from the bloc, after Greece and Cyprus pressed other EU states to speak out.
In a move that could further strain ties with Cyprus over exploration rights, Turkish Energy Minister Fatih Donmez was quoted by state-owned Anadolu news agency on Saturday as saying the Yavuz drillship would start drilling within a week.
Cyprus has discovered natural gas in areas rimming the south of the island in recent years, though none has been extracted.
Refinitiv Eikon shipping data showed the Yavuz arrived off Cyprus overnight.
A strongly-worded statement issued by the Cypriot presidency accused Turkey of a "grave violation" of the sovereignty of the island.
"This planned second drilling ... is an escalation by Turkey of its repeated violations of Cyprus's sovereign rights based on the U.N. Law of the Sea and international law, and is a most serious violation of the sovereignty of the Republic of Cyprus," Cyprus's presidency in Nicosia said in a statement.
The Yavuz is the second drilling ship to anchor off Cyprus in the past two months. It dropped anchor just north-east of the Karpasia peninsula, a jutting panhandle which is in territorial waters.
The other Turkish vessel, the Fatih, is anchored some 37 nautical miles off the western coast of the island in an area Cyprus claims is its Exclusive Economic Zone (EEZ), a maritime zone in which it has rights over its natural resources.
Turkey maintains some of the areas Cyprus is exploring in are either on its own continental shelf, or, if not, in zones where Turkish Cypriots have equal rights over any finds with Greek Cypriots.
Nicosia rejects the claim, saying it is not only inconsistent with international law, but that Turkey would not accept any international dispute settlement mechanism where its assertions could be put to the test.
Cyprus was divided in 1974 after a Turkish invasion triggered by a brief Greek-inspired coup. Several peacemaking efforts have failed and the discovery of offshore resources has complicated the negotiations.
(Reporting by Daren Butler and Michele Kambas; Editing by Kirsten Donovan and David Evans)