Greece on Thursday ratified a maritime border pact with Egypt, which has angered Turkey at a time of heightened tensions between Ankara and Athens over a dispute in the eastern Mediterranean.
The agreement is seen as a response to a Turkish-Libyan accord signed in 2019 allowing Turkey access to areas in the eastern Mediterranean where large hydrocarbon deposits have been discovered.
Tensions between Turkey and Greece escalated last month after a Turkish research vessel was dispatched with naval warship escorts into disputed Mediterranean waters.
The Oruc Reis ship was to carry out gas exploration off the Greek island of Kastellorizo, two kilometres (1.2 miles) from the Turkish coast.
Under their treaty, Egypt and Greece are now allowed to seek maximum benefit from the resources available in an exclusive economic zone, including oil and gas reserves.
In the Greek parliament, 178 lawmakers out of 300 voted in favour of ratifying the deal. A similar accord between Italy and Greece was approved on Wednesday.
Greek government spokesman Stelios Petsas said on Thursday that "their ratification is urgent" in view of "Turkey's illegal activities".
Prime Minister Kyriakos Mitsotakis told parliament another bill will extend Greece's coastal zone in the Ionian Sea from six to twelve nautical miles under international maritime conventions.