Turkey said on Friday it extended the operations of its seismic research vessel Barbaros Hayrettin Pasa off southeastern Cyprus until October 18.
Cyprus' internationally recognised Greek Cypriot government has long been at loggerheads with Turkey, which began drilling for oil and gas near Cyprus last year.
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The dispute stems from overlapping claims to regional waters linked to the split of the island between Greek and Turkish Cypriots. A breakaway Turkish Cypriot state in north Cyprus is recognised only by Ankara.
Turkey questions Cyprus' right to explore in the seas around the island because it maintains that the Nicosia administration does not represent the interests of Turkish Cypriots.
That argument is dismissed by Cyprus, which is legally recognised as representing the entire island.
Friday's announcement came three days after Turkey extended the operations of its Yavuz drill ship off Cyprus until October 12, in a move that Cyprus described as provocative. Greece, also locked in dispute with Turkey over east Mediterreanean waters, expressed concern.