A failure to de-escalate posturing in the eastern Mediterranean could lead to disaster amid tensions between Turkey and Greece, Germany's foreign minister has warned.
On a visit to the region, Heiko Maas reiterated the European Union's support for Greece over a maritime dispute in which both countries have dispatched their navies to shadow each other.
"The current situation in the eastern Mediterranean is equivalent to playing with fire," Mr Maas said after meeting his Greek counterpart Nikos Dendias. "Every little spark can lead to catastrophe."
Mr Dendias said Greece had shown it was ready for dialogue but warned that this was difficult when the country was being threatened.
“As we speak, Turkey continues to act illegally, to escalate, to provoke,” Mr Dendias said. “Instead of a de-escalation, we are witnessing new provocations. We are witnessing the attempt to implement expansionist aims against neighbours and allies.”
Greece announced that it would conduct navy and air force exercises in the eastern Mediterranean on Tuesday, prompting Turkey's defence ministry to respond by saying it would would carry out maritime training in a similar area.
The Greek three-day exercise will take place south-east of the island of Crete, near to where Turkey is searching for oil and gas.
Turkey’s President Recep Tayyip Erdogan earlier claimed that Greece was endangering the safety of all ships in the region.
“As of now, Greece will be the only one responsible for any negative development in the region,” Mr Erdogan said.
Greece announced the exercise after Turkey said that its research vessel the Oruc Reis – which has been accompanied by the Turkish navy – would continue its work until Thursday. Greece has repeatedly demanded its withdrawal, sent its own warships to the area and placed its armed forces on alert.
On Monday, Mr Erdogan refused to back down and even suggested that the work of the Oruc Reis could be extended.
"Turkey will not take even the smallest step back from the activities of either Oruc Reis or our naval elements escorting it," he said.
"With its stance that goes against international law, goodwill and neighbourly relations, Greece has thrown itself into a chaos from which it cannot find a way out."
Greece says it is defending its sovereignty from Turkish encroachment.
Earlier this month, Athens said a Greek frigate and a Turkish ship collided while shadowing the Oruc Reis.
The tensions have reverberated across the EU, with France dispatching ships to the area to support Greece’s monitoring of Turkey’s work.
Before he arrived in Athens, Mr Maas said there must be constructive dialogue.
“Turkey and Greece are our Nato allies,” he said. “There can only be solutions for the disputed questions surrounding the gas deposits in the eastern Mediterranean on the basis of international law and in sincere dialogue.
“The tensions are not just weighing on the relationship between the EU and Turkey. A further escalation can only damage all sides, but above all those immediately involved on the spot.”
“The windows for dialogue between Greece and Turkey must now be opened further and not closed. For this, instead of new provocations, we finally need steps towards de-escalation and a start to direct talks,” he said.
Germany currently holds the rotating presidency of the European Union, and a spokesperson for Chancellor Angela Merkel said it was essential to remain in dialogue with both sides.
"The aim is for Greece and Turkey to resolve their problems with each other directly," the spokesman said.
Mr Maas’s trip comes ahead of a meeting of EU foreign ministers in Berlin later this week, at which Turkey will be discussed.