NATO members Greece and Turkey on Tuesday began talks in Athens to try once more to settle their standoff over eastern Mediterranean borders and energy rights.
Ankara ratcheted up the pressure a notch on Monday with a diplomatic note to Israel, Greece and the European Union.
It told them to seek its permission before assuming work on a proposed undersea power cable in disputed eastern Mediterranean waters, according to Turkish state media.
EU members Greece and Cyprus, along with Israel, have signed a trilateral Memorandum of Understanding for the construction of an underwater power cable that will run through the Mediterranean seabed and act as an emergency back-up power source.
Hostilities flared last year when Ankara sent a research ship accompanied by a navy flotilla into waters near the Turkish coast which belong to Greece.
Those waters are thought to be a possible source of natural gas reserves.
Turkey has not de-escalated its stand-off with Greece in response to diplomatic outreach. European Council chief Charles Michel has already warned that EU member states would now consider “the means at our disposal”, which most probably means sanctions.
Tuesday’s meeting follows one in Istanbul in January, the first direct talks between the two sides on the dispute in nearly five years — and which happened only after pressure from the EU.