President Recep Tayyip Erdogan on Friday said Turkey had made its biggest-ever discovery of natural gas after completing new exploration work in the Black Sea.

Erdogan said the 320-billion-cubic-metre deep sea find was made at a site Turkish vessel Fatih began exploring last month, adding he hoped to see the first gas reach Turkish consumers in 2023, the 100th anniversary of the birth of the modern republic.

"Turkey made the biggest discovery of natural gas in its history in the Black Sea," a delighted Erdogan said during a speech in Istanbul's Dolmabahce Palace. "My Lord has opened the door to unprecedented wealth for us," he enthused.

The Fatih, Turkey's first drilling vessel, is named after Ottoman Sultan Fatih Sultan Mehmet, who conquered Constantinople -- current-day Istanbul -- in 1453. The vessel made the discovery in the Tuna-1 field off the coast of Eregli town in the northern province of Zonguldak after beginning the search on July 20, Erdogan said, adding that he hoped so see new finds in the same region.

Finance Minister and Erdogan's son-in-law, Berat Albayrak, speaking aboard the Fatih, said the discovery and future potential would help reduce Turkey's widening current-account deficit by addressing the country's high annual energy import bill.

Turkey is hugely dependent on Russia for its energy and has been keen to diversify its supplies. This month, Erdogan ordered the resumption of controversial energy exploration off Turkey's southern coast close to a Greek island in disputed eastern Mediterranean waters.

The issue has pitted Ankara against Greece, Cyprus and the European Union, and exacerbated tensions with France, which has stepped up its military presence in the region. Erdogan showed no sign of yielding to the EU's calls to immediately end the eastern Mediterranean search.

"We will accelerate our activities in the Mediterranean with the deployment by the end of the year of (drilling ship) Kanuni, which is currently under maintenance," he said. "God willing we expect similar good news," Erdogan added.