"We Europeans must be clear and firm, not with Turkey as a nation or as a people, but with the government of President (Recep Tayyip) Erdogan," Macron said on Thursday.

The Turkish government is engaging in "unacceptable behaviour" by drilling for gas in waters claimed by Cyprus; claiming an exclusive economic zone in waters also claimed for that purpose by Greece; and other "provocations," Macron insisted.

"We want to avoid any escalation," he added.

"But avoiding escalation cannot mean passivity or acceptance."

Turkey lashed out in response, with the Foreign Ministry calling Macron "arrogant" and reverting to "old colonial reflexes".

Macron is not in a position to make decisions on maritime zones, the ministry in Ankara said, adding that France should favour reconciliation and dialogue instead.

Macron's "individual and nationalist stance encourages tension and puts the major interests of Europe and the EU at risk," the ministry said in a statement.

NATO members Greece and Turkey have for weeks been sparring about natural gas reserves and maritime boundaries, with both claiming the right to prospect and drill for energy resources in the same part of the eastern Mediterranean.

The stand-off has resulted in Turkey sending research vessels into contested waters; EU allies dispatching ships to the region to help Greece uphold its claims; and both Turkey and Greece carrying out manoeuvres with frigates and fighter jets.

Greek Prime Minister Kyriakos Mitsotakis threatened Turkey with EU sanctions if it doesn't "come to its senses" before a meeting of European Union leaders this month.

EU heads of government would have "no other option than to implement effective sanctions," wrote Mitsotakis in the Frankfurter Allgemeine Zeitung newspaper.

"We need dialogue but not at gunpoint."

He called on Turkey to return to the negotiating table and added that, if no agreement can be reached, the International Court of Justice should decide.

The eastern Mediterranean will likely take centre stage at an EU summit scheduled for September 24-25.

Australian Associated Press