Turkish President Recep Tayyip Erdogan on Sunday said Turkey would not back down from gas exploration in Cyprus after southern European leaders urged Ankara to stop.
"We continue and will continue to search in those areas that are ours," Erdogan said during a televised speech in Istanbul.
"Someone has given an order. They will apparently arrest our boats' personnel. You will come off badly if you do so," Erdogan warned, after Cyprus reportedly issued arrests warrants for crew members of Turkey's drilling ship, Fatih, last week.
After a summit of the southern European Union countries in Valletta, the seven nations issued a joint declaration on Friday, expressing "serious concern over actual or potential drilling activities within Cyprus' exclusive economic zone".
They urged the EU to keep an eye on the issue "and, in case Turkey does not cease its illegal activities, to consider appropriate measures in full solidarity with Cyprus".
The Turkish foreign ministry on Saturday said the declaration was "biased" and contrary to international law, accusing the European Union of siding with EU members Cyprus and Greece.
The discovery of huge gas reserves in the Mediterranean has fuelled the race to tap underwater resources.
Erdogan on Sunday also hit out at French President Emmanuel Macron over his support for Cyprus.
Macron said on Friday the EU would "not show weakness on this matter".
"What business does France have here?" Erdogan said. "Turkey is a guarantor power in Cyprus. Greece and the UK are guarantor powers as well. What are you?
"Are you making such statements for Total? Show you have the power of attorney. So it means you have left the presidency and have now begun work as a lawyer," he quipped.
Energy giants Total of France and Italy's ENI are heavily involved in exploring for oil and gas off Cyprus as well as ExxonMobil.