Turkey’s redeployment of a research vessel to the eastern Mediterranean will cause new tensions in the region, the European Union warned on Monday, after Greece accused Ankara of lacking credibility in talks over disputed maritime boundaries.
EU foreign affairs chief Josep Borrell said the return of the Oruc Reiss to conduct seismic studies was "regrettable".
“This will lead to new tensions instead of contributing to the de-escalation efforts that we were calling for at the last European Union Council,” he said, after meeting with EU foreign ministers in Luxembourg.
While there was no suggestion of sanctions being discussed on Monday, Brussels has previously said it would punish Turkey if it continued its operations in the region, which have angered Greece and Cyprus in particular.
European Commission President Ursula von der Leyen warned Turkey earlier this month against taking provocative measures and said the EU would "use all its instruments and options available" if Turkish unilateral actions did not cease.
Ankara withdrew the vessel last month to allow for talks to resume with Athens over the contested boundaries before an EU summit at which Cyprus had pushed for sanctions on Turkey.
But on Monday, Turkey issued a maritime advisory that the Oruc Reis would be dispatched back to the region, leading to a stinging rebuke from Greece only days after the two countries' foreign ministers met in Slovakia in a sign that tensions could have been easing.
Turkey insists it is operating within its continental shelf and has rejected Greece’s objections. France, which has been particularly critical of Ankara, said Turkey must abstain from new provocations “and show concrete evidence of good faith”.
Greek Prime Minister Kyriakos Mitsotakis said the “new unilateral act is a severe escalation on Turkey’s part”.
Greece’s foreign ministry also accused Turkey of lacking credibility and said it had proven itself to be unreliable in prospective talks over the dispute.
It said the planned return of the Oruc Reis constituted "a major escalation and direct threat to peace and security in the region".
It accused Turkey of undermining dialogue, ignoring international law and stoking tensions in the region by initiating surveys only 6.5 nautical miles from Greece’s continental shelf, south of the island of Kastelorizo.
“Just a few days after the meeting between the Ministers of Foreign Affairs of Greece and Turkey, during which the Turkish side committed to proposing a date for the exploratory talks, Turkey’s unreliability and the fact that it does not sincerely desire dialogue have once again become evident,” the Greek foreign ministry said.
“Turkey is persisting with the use of aggressive and illegal tactics of past centuries, thus confirming its role as the prime factor for instability and violation of international legality in the region.”
Greek government spokesman Stelios Petsas said the move showed that Turkey “lacks credibility”.
Turkish Energy Minister Fatih Donmez wrote on Twitter that the Oruc Reis had weighed anchor after undergoing maintenance.
"We will continue to explore, dig and protect our rights," he wrote.
Turkish Defence Minister Hulusi Akar said Turkey's navy would provide protection and support if necessary.
The standoff comes at a particularly tense time as Turkish-backed northern Cyprus goes to the polls for its presidential election.
It pits incumbent Mustafa Akinci, who supports the reunification of the Northern Territory with Greece-backed southern Cyprus, against Prime Minister Ersin Tatar, a favourite of Turkish president Recep Tayyip Erdogan.