President Recep Tayyip Erdogan on Tuesday warned foreign energy companies not to "overstep the mark" in the Mediterranean, after Turkey's warships blocked an Italian drilling vessel seeking to begin exploration for gas off Cyprus.
The growing standoff between Turkey and Cyprus over exploiting energy resources in the eastern Mediterranean risks further complicating stalled efforts to reunify the island following the collapse of peace talks last year.
"Don't think that we have ignored the opportunistic attempts to search for natural gas in Cyprus waters and Aegean coast," Erdogan said in a televised speech to his party in parliament.
"We warn those overstepping the mark with miscalculations in Cyprus and the Aegean," Erdogan added.
Italy's energy giant ENI said its ship had been ordered to stop by Turkish ships last week over "military activities in the destination area" as it was on course to start exploring in block 3 of Cyprus's exclusive economic zone.
Cyprus has been divided since 1974 when Turkish troops invaded and occupied the northern third of the island in response to a Greek military junta-sponsored coup.
While Greek-majority Republic of Cyprus is internationally recognised, the breakaway Turkish Republic of Northern Cyprus is recognised only by Ankara.
Ankara and Cyprus have long argued over the eastern Mediterranean, and Turkey has been stringent in defending the claims of Turkish Cypriots for a share.
Cyprus said on Thursday that exploratory drilling by Italy's ENI and France's Total had found gas reserves elsewhere off the island.
But Erdogan warned foreign companies working with the Cyprus government that "they should not be exploited as tools for a work that exceeds their limits and strengths".
He even compared Turkey's response over the issue to its military operations in northern Syria, which Turkey portrays as a fight against terror groups.
"Like on our southern border with our 'Euphrates Shield', 'Olive Branch' operations, we are ruining those who make mistaken calculations and their scenarios."
The European Union, where Cyprus is a member, has made clear it is keeping a close eye on Turkey's behaviour.
EU President Donald Tusk on Monday spoke with Cypriot President Nicos Anastasiades, urging Turkey on Twitter to "avoid threats or actions against any EU member".
He added Turkey should "instead commit to good neighbourly relations, peaceful dispute settlement and respect for territorial sovereignty."