French President Emmanuel Macron said Europe needed "a more united and clear voice" on Turkey which is "no longer a partner".
Macron categorised some of Turkey's actions as "inadmissible practices" including its drilling activities near Cyprus that are "not worthy of a great state".
"We Europeans must be clear and firm with, not Turkey as a nation and a people, but with the government of President Erdogan which today has had unacceptable actions," President Macron said at a press conference ahead of a Southern European summit.
Macron said Europe should avoid an escalation with Turkey but said that Erdogan needed to "clarify" Turkish actions.
His comments come as rising tensions in the Eastern Mediterranean between Turkey and Greece are likely to dominate the summit of Southern European countries.
Macron also said that he would launch a French-German initiative to welcome migrants following the fire at the Moria camp in Lesbos. But he gave few details about a plan to do so, which he said would be discussed today.
Tensions rose in the region after Ankara began exploratory drilling in disputed waters between Crete and Cyprus.
Greece and Turkey, both of whom are members of NATO, have deployed naval forces to the area.
Greece, in response, has also said that it plans to extend its territorial waters from six to 12 nautical miles in response to the current crisis.
Macron said Europe needed to clarify their "red line" and to reengage with Turkey. The EU has previously tried to mediate with Turkey over the drilling activities.
"All of us Mediterranean nations need to live in peace," Macron added.