Turkey's push to secure a share of the resources has deepened tensions with historic rival Greece and with Cyprus, whose northern third the Turkish military has occupied since a failed coup attempt that sought to unite the island with Greece in 1974.
But in a message on NAVTEX, the global maritime navigational telex system, Turkey said late Monday the seismic vessel's stay in the disputed waters would be extended until September 12.
Greece says islands must be taken into account in delineating a country's continental shelf, in line with the United Nations Law of the Sea, a convention Turkey hasn't signed. "Turkey will not bow to the language of threats, intimidation and blackmail, especially in the eastern Mediterranean, and will continue to defend its rights under worldwide law and bilateral agreements", he said.
The European Union has repeatedly urged Turkey to stop the exploration activities and threatened to slap sanctions on Ankara if it refused to solve the dispute through talks.
While Turkish President Recep Tayyip Erdogan said Greece is "incompetent" and as "bait" that is being used by other countries, the New Democracy government has responded with a tentative plan to arm up and buy more fighter jets, reports said.
Turkish Foreign Minister Mevlut Cavusoglu attends a press conference in Ankara, Turkey, August 25, 2020.
Ankara's relations with Athens have deteriorated sharply, with strains over issues including migration and Turkey's decision to reconvert Hagia Sophia museum into a mosque.
Images published in the media last week showing Greek soldiers arriving on the island of Kastellorizo, known as Meis in Turkish, appear to have opened another front in the dispute.
The island is only two kilometres (1.2 miles) from Turkey's famed seaside town of Kas in the Antalya province.
Greece has attempted to illegally restrict Turkey's maritime territory, trying to box it in to its shores based on small Greek islands near the Turkish coast.
Greece has also recently carried out military drills - including with France - meant to intimidate Turkey into stopping energy exploration, as well as illegally armed Aegean islands, in violation of longstanding peace treaties.