After visiting Cyprus earlier, US Secretary of State Mike Pompeo is scheduled to visit Greece to try to de-escalate the simmering tension with Turkey over who has rights to the seas around Greek islands.

Greece and Turkey have been at near-conflict flash points for weeks, the tension dropping after Turkish President Recep Tayyip Erdogan withdrew the energy research vessel and warships away from the island of Kastellorizo.

While Turkish officials said the ships will return, Erdogan cooled down his fiery rhetoric to say he did it to give diplomacy a chance but that gesture came just ahead of a Sept. 24-25 showdown with the European Union.

Prime Minister Kyriakos Mitsotakis wants the EU to impose tough and meaningful sanctions if Turkey doesn't keep the ships away from Greece's Continental Shelf or he can't reach an agreement with Erdogan.

Besides Greece-Turkish relations, Pompeo will discuss military cooperation with Greek officials and likely will meet Mitsotakis, said Kathimerini, without explaining why a top-ranking American official wouldn't meet Greece's leader.

On Cyprus, Pompeo called for Turkey to calm down and not proceed to continue with drilling in waters off the island but his visit, coming after the US partially lifted an arms embargo in place for decades set off anger in Ankara, bringing a setback.