Greece and Turkey have started their first direct talks in nearly five years over their tense Eastern Mediterranean stand-off, following pressure from the European Union and NATO.

The Istanbul meeting is not expected to lead to a significant shift in the frosty relations of the two NATO neighbors, who were on the verge of a military conflict last August.

However, it adds to Turkish President Recep Tayyip Erdogan's efforts to repair damaged relations with Europe, as the country prepares to deal with a potentially less friendly U.S. administration under President Joe Biden.

Greek Foreign Minister Nikos Dendias said over the weekend that Athens was going into the so-called exploratory talks "in good faith," a view echoed by his Turkish counterpart Mevlut Cavusoglu.

The two countries held 60 rounds of talks between 2002 and 2016, but the negotiations failed to resolve a dispute that has lingered for much of the past century.

Hostilities flared last August when Ankara sent a research ship accompanied by a navy flotilla into waters near the Turkish shore to explore for undersea oil and gas in Eastern Mediterranean waters that Greece claims as part of its continental shelf and Exclusive Economic Zone (EEZ), a claim Turkey disputes.

Turkey is furious that Greece is using its vast web of islands to lay claim to huge swathes of the Aegean and Mediterranean Seas. The two sides cite a range of decades-old treaties and international agreements to support their conflicting claims.

NATO has set up a hotline to prevent an armed conflict, while Germany has led the efforts to end the dispute through negotiations, ensuring Turkey is not further isolated.

It will be challenging as Athens and Ankara disagreed over the agenda for these talks just last week.

Greece is keen to limit the discussions to continental shelf borders and the size of the EEZ. 

But Ankara also accuses Athens of illegal deployment of its troops on some of its islands and wants to discuss aerial zones, a separate issue which came to the fore after a Greek pilot was killed when his jet collided with a Turkish one in 2006.

"It's not right to choose one [subject] and say, 'we're holding exploratory talks on this'," Cavusoglu said last week.

Michael Tanchum, a security and energy expert, argues the involvement of a third party such as the U.S. or Germany will benefit the negotiations.

"The likely outcome of such adjudication would invalidate the use of some small Greek islands near Turkey's mainland ... while upholding the use of larger islands and more distant islands," Tanchum said.

Greece's foreign minister has suggested the dispute could be submitted for arbitration in The Hague if the exploratory talks collapse.

The Istanbul meeting comes amid a sudden shift in diplomacy aimed at thawing relations that have frozen EU accession talks, which Turkey started in 2005.

Cavusoglu was in Brussels for meetings with top EU officials last week and Ankara hopes for a return visit at the end of February or early March.

But European Commission President Ursula von der Leyen said in a tweet after the meeting that, as well as talks, she expected "credible gestures on the ground."

France has led EU condemnation of Turkey's military interventions in Syria and Libya as well as Erdogan's support for Azerbaijan in the Nagorno-Karabakh war against Armenia last year.

The EU ultimately decided to draw up an expanded list of Turkish targets for sanctions last month.