Greece and Libya agreed to hold talks on marking out their maritime zones amid tension in the Eastern Mediterranean that Athens said was caused by Turkey's "neo-Ottoman aspirations".
The announcement of negotiations by Greek Prime Minister Kyriakos Mitsotakis came after Turkey this week reaffirmed its commitment to a 2019 maritime deal with Libya, which angered Greece and Cyprus.
Athens said the agreement was a serious breach of international law that disregarded the rights of other Mediterranean nations.
But Mr Mitsotakis said on Wednesday that leaders had "agreed on the immediate resumption of talks between Greece and Libya on the delimitation of the maritime zones".
The issue feeds into growing tension between Athens and Ankara over borders, migration and gas deposits in the Eastern Mediterranean.
Turkey angered Greece by carrying out seismic research in disputed Mediterranean waters, while tension flared last year when thousands of asylum seekers in Turkey tried to storm the Greek land border.
Greek Foreign Minister Nikos Dendias is due to travel to Turkey on Thursday for face-to-face talks on the maritime border dispute.
Nikolaos Panagiotopoulos, Greece's Defence Minister, said Ankara’s growing military presence destabilised the region and that Europe could “take more steps” if Turkey did not “change its behaviour”.
He said at a Chatham House event that Turkey was “escalating tensions” by dispatching military forces around the region.
“I would like to stress the fact that the primary source of this growing instability in our region has largely been Turkey’s neo-Ottoman aspirations to an aggressive posture,” he said.
Mr Panagiotopoulos said Turkey was pursuing a policy “characterised by disrespect of international law and good neighbourly relations”.
“Everybody is aware of Turkish military forces and assets dispatched to many countries – northern Iraq, Syria and Libya,” he said.
"This is an enhanced military presence all over the region, for the sake of maintaining peace and stability. That's the Turkish position.
“In our mind, though, it has a certain destabilising element overall as well.
"We do believe that Turkey does need to change its behaviour, otherwise Europe, undoubtedly, will have to take more steps and more measures."
In addition to the border disputes, Greece and Turkey have long traded accusations over migration on Europe's borders.
The Turkish coastguard accuses Greece of illegally pushing migrants back to Turkey without allowing them to apply for asylum in the EU.
Athens rejects the allegations and accuses Turkey of orchestrating attempts by migrants to enter Greece illegally.
Thousands of people tried to force their way into Greece last year, in what Mr Panagiotopoulos claimed was an organised effort by Turkey.
“This operation was co-ordinated by Turkey with the sole purpose to threaten our security and undermine our country’s resilience and social cohesion,” he said.
However, he called for the countries to reach an understanding that he hoped would extend to “the full range of our bilateral relations”.
Separately, Mr Panagiotopoulos called for Greece and the UK to continue their “excellent co-operation” after Brexit.
“There is a certain mutual interest in remaining close partners in security and defence,” he said.
“Our position is that the UK should remain a strategic partner for the EU, taking into account the security interests of both parties.”
