ATHENS – Greek Prime Minister Kyriakos Mitsotakis said he's willing to discuss seas boundaries with Turkey, which pulled an energy research vessel and warships away from the island of Kastellorizo, but only if he sees “tangible evidence,” of de-escalating the confrontation.

He told reporters during a visit to Athens by European Council President Charles Michel that there's time for Greece and Turkey to work out differences before a Sept. 24-25 European Union showdown with President Recep Tayyip Erdogan.

Mitsotakis said unless there's a resolution he wants the EU to impose tough and meaningful sanctions and not just lenient actions such as the soft penalties implemented for Turkish drilling for oil and gas in Cypriot waters.

“Turkey has time before and after the summit to continue with the first encouraging step,” Mitsotakis said, referring to the Turkish ships leaving Greece's Continental Shelf although Turkey said the energy ship the Oruc Reis was moved for maintenance and would return.

The EU's support for Greece, he said, acknowledged that the “European Union’s strategic interests are also at stake” in the region, adding that efforts at de-escalation must have “continuity and consistency,” said Kathimerini.

Michel, who has been reluctant to get tough on Erdogan, the bloc fearing the Turkish leader will send more refugees and migrants through Greece who had gone to his country fleeing war, strife and misery in their, said the EU must take a “strict” stance but Germany, home to four million Turks, has resisted that.

“We are also ready to open our arms and show that a positive agenda is possible if there is a common will for these principles to be respected,” Michel added.

Turkey moved toward Greek waters after a deal with Libya dividing the seas between them, claiming seas around Greek islands, Greece countering with a similar agreement with Egypt.

That set off a near-conflict off Kastellorizo with ships from each country's Navy closely monitoring each other leading to the EU and NATO, the defense alliance to which both belong but which had done nothing about Turkish violations of Greek waters and airspace, trying to ratchet down the tension and host talks.