President Recep Tayyip Erdogan yesterday warned Turkey would make "no concessions" in the eastern Mediterranean and told Greece to avoid taking steps that could lead to its "ruin". His remarks come just hours after Athens said it would launch military exercises with France, Italy and Cyprus in the region, where tensions between the two neighbours have escalated in recent weeks. Greece and Turkey are already divided on significant issues including migration and Byzantine heritage in Istanbul, formerly Constantinople. But the discovery of hydrocarbon reserves in the eastern Mediterranean has further strained relations, with Turkey rejecting calls from the EU and Athens to immediately stop energy exploration in the region. Turkey sent the Oruc Reis research vessel accompanied by warships to disputed waters on August 10. Its activities were meant to end on last Sunday but were extended to Thursday.