The ministers were expected to debate sanctions and other policy options that might deter Turkey from prospecting for potential oil and gas reserves in parts of the eastern Mediterranean where Greece claims — but has not tried to exercise — exclusive rights.
Maas, who visited both Athens and Ankara on Tuesday, stressed the need to “create the conditions for Turkey and Greece to resolve their problems directly with each other.”
“The situation remains very difficult,” Maas said. “The precondition for these talks is that the maneuvers that are going on in the eastern Mediterranean be ended ... because for sure the parties won’t sit down at the table if warships are facing off in the eastern Mediterranean.”
Tensions have been running high for weeks after Turkey sent its survey vessel, Oruc Reis, to carry out seismic research, escorted by Turkish warships, between Crete, Cyprus and southern Turkey. Athens, which says the ship is operating over Greece’s continental shelf, sent warships to observe and track the Turkish flotilla.
Turkey disputes Greece’s claims, and accuses Athens of trying to grab an unfair share of the eastern Mediterranean’s resources.
Both countries have been conducting military maneuvers in the area. On Thursday, France was set to join Italy, Greece and Cyprus in three-day air and sea military exercises off the east Mediterranean island. Greek military officials said Thursday the United Arab Emirates have sent four fighter jets and five military transport planes to an airbase on Crete for joint training with Greek forces.
Turkey, meanwhile, said it would hold live-fire exercises Sept. 1-2 off its southern coast, opposite Cyprus. It also extended Oruc Reis' operations until Sept. 1.
President Donald Trump on Wednesday held separate calls with the leaders of Greece and Turkey. NATO Secretary-General Jens Stoltenberg said Thursday he was in “constant contact” with Athens and Ankara.
Cypriot Foreign Minister Nikos Christodoulides said Turkey’s “illegal and provocative actions" threatened Europe's credibility.
“A union of 27 member states must stand up for international values, for a global, international order based on the values and principles of the European Union," he said.
Turkish officials, meanwhile, accused France of stoking tensions by holding military exercises with Greece and Cyprus. Defense Minister Hulusi Akar said Turkey would not be deterred by the show of force.
“To believe that it would be possible to thwart the Turkish Armed Forces operations with exercises and similar activities is nothing more than a pipe dream,” Akar told the state-run Anadolu Agency.
Turkish President Recep Tayyip Erdogan said his country “will never compromise on what belongs to us. We are determined to do whatever is necessary in political, economic and military terms.”
Greek Prime Minister Kyriakos Mitsotakis said Greece is planning to exercise its legal right to extend its territorial waters along its western coastline, which faces Italy, from six to 12 nautical miles. This wouldn't affect the territory at the center of the Greek-Turkish dispute, however.
Turkey has warned in the past that an extension of Greek waters to 12 nautical miles in the Aegean Sea would be seen as a reason to declare war on Greece.
On Thursday, Greece's parliament ratified an agreement with Egypt demarcating maritime boundaries and Exclusive Economic Zones between the two countries in the Mediterranean. The treaty has angered Turkey.
Akar, the Turkish defense minister, reiterated that Turkey favored dialogue with Greece, but was determined to safeguard its rights.
“If our Greek counterparts agree, we would be pleased to host them here,” Akar said.
Greek government spokesman Stelios Petsas said the tensions were not being generated by Greece.
"We are waiting for the Turkish side to officially express its positions. One way of course to express oneself is by ending any provocative action in the area,” he said.
Geir Moulson reported from Berlin. Derek Gatopoulos in Athens, Greece, and Lorne Cook in Brussels, contributed to this report.