Diplomats from NATO members Greece and Turkey failed to reach a breakthrough on Tuesday during the latest round of talks on their standoff over eastern Mediterranean borders and energy rights.

Greek foreign minister Nikos Dendias told reporters afterwards that his country was “participating in these talks in good faith”.

But the two sides seemed far apart both on the scope and details of the talks.

Turkish President Recep Tayyip Erdogan said afterwards it was “out of the question for us to make any concessions”.

Addressing a news conference, he added: “Turkey’s determination in the eastern Mediterranean remains entire.”

Tuesday’s talks were the second meeting this year after the two sides met in Istanbul in January, ending a nearly five-year pause in the dialogue – and taking place only after EU pressure.

Another meeting is scheduled in Istanbul, reported Greek state broadcaster Hellenic Broadcasting Corporation – known by its Greek acronym ERT. But more than 60 such meetings since 2000 have yielded scant progress.

The latest talks did not start in the best of conditions, after a diplomatic note from Ankara a day earlier drew a line in the sand.

The note was addressed to Israel, Greece and the EU, Turkish media reported, telling them to seek Ankara’s permission before proceeding with work on a proposed undersea power cable in disputed eastern Mediterranean waters.

Both sides cite a range of decades-old treaties and international agreements to support their conflicting territorial claims.

Hostilities flared last year when Ankara sent a research ship accompanied by a navy flotilla into waters near the Turkish coast that Greece asserts belongs to it – a claim that the EU supports.

Those waters are thought to be a possible source of natural gas reserves.

‘Provocations’

Turkey is furious that Athens is using its web of islands to lay claim to huge swathes of the Aegean and Mediterranean seas.

But at a December EU summit, member states drew up a list of Turkish targets for sanctions over what it said had been Ankara’s “unilateral actions and provocations” in the eastern Mediterranean.

A Greek diplomat said the bloc’s March summit would return to the question. Greece is also counting on the support of US President Joe Biden, the same source said.

NATO chief Jens Stoltenberg also expressed “serious concerns” over Turkey’s actions in comments to European lawmakers on Monday.

He cited not just Ankara’s claims in the eastern Mediterranean, but also its decision to buy the Russian air defence system S-400 and its record on rights at home.

Ankara, however, remains defiant.

In a videoconference with military officers, Turkey’s defence minister Hulusi Akar called on Athens to abandon its “uncompromising and provocative attitudes”.

He denounced what he said were Greece’s efforts to drag the EU and the US into what was essentially a bilateral dispute.

“They will not get anywhere like this,” he said.