The Turkish navy said on Sunday that the research ship Oruc Reis, at the centre of an energy rights row with Greece, will be sent back in the sea area south of the Greek island of Kastellorizo.
Turkey withdrew the ship in September ahead of diplomatic attempts to resolve the dispute.
Now, Ankara has said that the ship will again spend 10 days conducting seismic research in the eastern Mediterranean until Oct. 22.
The vessel will also be accompanied by two other ships, Ataman and Cengiz Han.
Earlier this month, the EU threatened to bring in sanctions on Turkey if it failed stop illegal drilling and energy exploration activities in Greek and Cypriot waters.
Turkey said the threat of sanctions was “unconstructive”.