Greece on Tuesday has formally informed the UN that in its view, the Turkey-Libya deal on maritime boundaries in the Mediterranean Sea was invalid, government spokesman Stelios Petsas said.
Petsas said that Letters detailing the position were sent to the UN Security Council and the Secretary-General.
Meanwhile, Prime Minister Kyriakos Mitsotakis said his intentions were to include the issue on the agenda of the EU summit on Friday and seek support from member countries.
The latest steps were set to raise tensions in the eastern Mediterranean by another notch. However, Greece had already expelled the Libyan ambassador to Athens over the issue.
Foreign Minister Mevlut Cavusoglu said sometimes ago that Athens insisted that the deal on maritime boundaries Turkey signed with Libya was to protect their rights in the eastern Mediterranean.
He said that the deal was under international law and would ensure a fair share of resources.
The deal comes amid Turkish offshore drilling activities near Cyprus which angered the EU and Greek Cypriots on the divided island, further straining traditionally poor relations between Ankara and Athens.
Cyprus, which joined the EU in 2004, considered the drill area to be part of its exclusive economic zone.
However, Ankara maintained that its gas exploration was in line with international law.
The island-state had, since 1974, been split into a predominantly Greek south and a Turkish north, whose sovereignty is recognised only by Ankara.
Edited by: Yahaya Isah/Emmanuel Yashim