(ANSA-AFP) - ANKARA, 01 SET - Turkey has extended until mid-September its controversial natural gas exploration mission in east Mediterranean waters claimed by Greece. Ankara deployed the Oruc Reis research vessel and warships to the disputed waters on August 10 and prolonged the mission twice, raising tensions with Greece and the rest of the EU. The most recent of the two extensions was until Tuesday. But in a message on NAVTEX, the international maritime navigational telex system, Turkey said late Monday the mission would now be extended until September 12. Hours earlier, Turkish President Recep Tayyip Erdogan said in a televised speech that the Oruc Reis was "continuing its activities with determination." "God willing, we hope to get good news from the Mediterranean in a short span of time, too, as we got in the Black Sea," Erdogan said. Erdogan was referring to Turkey's discovery of what officials said were 320-billion-cubic-metres of natural gas in the Black Sea, the biggest in Turkey's history. Ankara's relations with Athens have deteriorated sharply, with strains over issues including migration and Turkey's decision to convert Byzantine-era churches into mosques. (ANSA-AFP).