French President Emmanuel Macron has urged fellow European leaders to stand up to the Turkish government and what he calls "unacceptable" provocations as Ankara seeks to expand its energy resources and influence in the eastern Mediterranean.
Leaders of European Union countries that border the Mediterranean Sea were holding an emergency summit in Corsica amid fears of an open conflict with Turkey stemming from mounting tensions over offshore oil and gas drilling.
Turkish leaders have lashed out at France and the EU for siding with Greece and Cyprus in the dispute.
"Turkey is no longer a partner in this region," Macron told reporters ahead of the island summit.
"We Europeans need to be clear and firm" with the government of Turkish President Recep Tayyip Erdogan about its "inadmissible behaviour," he said.
Macron didn't elaborate on what specific actions he wants European countries to take, but said they should lay out "red lines" with Turkey and try to restart dialogue.
"We Mediterraneans need to live in peace," he said.
Greece and Turkey have deployed naval and air forces to assert competing claims over energy exploration rights in the eastern Mediterranean. Turkish survey vessels and drill ships continue to prospect for gas in waters where Greece and Cyprus claim exclusive economic rights.
France is carrying out military patrols in the region in a show of support for Greece and Cyprus, and the EU is mulling new sanctions against Turkey.
Separate from the diplomatic discussions, Turkish and Greek military officials met Wednesday at NATO headquarters, as part of ongoing meetings aimed at reducing the risk of armed conflict. Greece and Turkey both are NATO members.
Speaking Thursday to EU lawmakers, Greek European Affairs Minister Miltiadis Varvitsiotis appealed for support from European partners, saying the tensions over energy rights "constitute by themselves a grave threat to our common security architecture."
He said that Turkey is looking beyond Greece and is "a major destabilising factor in the wider area," citing Turkish government actions in Libya, Syria and beyond.
"At the end of the day, we will defend ourselves, even alone."
At the Corsica summit, France wants the European leaders to push for resuming German mediation in the eastern Mediterranean dispute.