Turkey's defence ministry on Tuesday accused Athens of violating two international treaties by planning aerial exercises near two Greek islands in the Aegean Sea.
The two uneasy NATO neighbours have spent much of the past year feuding over maritime borders and energy exploration rights in disputed parts of the Aegean and eastern Mediterranean.
Greek Foreign Minister Nikos Dendias tweeted Tuesday that "Turkey has been constantly intensifying its illegal actions in the eastern Mediterranean, flagrantly violating international law".
His comments came a day after Greece posted a message on the Navtex naval communications system announcing plans for "aeronautical exercises" just north of its Limnos island and south of the Ikaria island on Wednesday.
Turkey does not lay claim to the two Aegean islands but insists they must remain free of all military activity under the terms of the 1923 Lausanne and 1947 Paris peace treaties that followed World War I and World War II.
Turkey's defence ministry called Greece's plans to stage air drills near the islands a "violation of their non-military status".
The Turkish navy also issued three of its own Navtex messages pointing out that it had reserved the right in January to conduct "firing exercises" in the Aegean until the end of the year.
The latest exchange threatens to revive tensions that resulted in the two countries staging rival military exercises in the eastern Mediterranean in August.
Their warships also collided during one incident that came as Turkey was conducting seismic research activity near Greece's easternmost island.
Both countries are members of NATO but Greece is also part of the European Union and has the bloc's full backing in the dispute.
Brussels has spent months discussing the possibility of sanctioning Turkey for drilling for natural gas in waters claimed by Cyprus and Greece.
Tensions eased slightly after a powerful earthquake hit the Aegean in October.
The two nations' leaders exchanged rare phone calls and promised each other assistance recovering from damage from the quake that killed 116 people in Turkey and two in Greece.
