President Tayyip Erdogan said on Friday Turkey discovered its biggest ever natural gas field holding 320 billion cubic metres (11.3 trillion cubic feet) in the Black Sea, and more could be found as the country works to provide it by as soon as 2023.
If the gas can be commercially extracted, the discovery could help Ankara cut its current dependence on imports - from countries such as Russia, Iran and Azerbaijan - for a substantial amount of its energy needs.
"Turkey has realised the biggest natural gas find of its history in the Black Sea," Erdogan said, adding that Turkey aims to become a net energy exporter.
The Fatih drill ship began work late last month in the Tuna-1 zone, about 100 nautical miles north of the Turkish coast in the western Black Sea. All tests and engineering work has been completed, Erdogan said.
"This reserve is actually part of a much bigger source. God willing, much more will come. As a country that depended on the outside for gas for years, we look to the future with more security now," he said. "There will be no stopping until we become a net exporter in energy."
Any reduction in Turkey's energy import bill, which stood at $41 billion last year, would boost government finances and help ease a chronic current account deficit which has helped drive the lira to record lows against the dollar.
The currency has strengthened since Erdogan first told energy executives on Wednesday that he had "good news" to announce. The lira slid however as he detailed the find and was down 0.4 percent at 1247 GMT.
Officials and analysts have cautioned that it could take up to a decade for any gas from the Black Sea find to come online, and would need billions of dollars of investment to build up the infrastructure for production and supply.
Turkey has been exploring for hydrocarbons in the Black Sea and in the Mediterranean - where its survey operations in disputed waters have drawn protests from Greece and Cyprus.
Erdogan said Turkey will accelerate operations in the Mediterranean.