Turkish President Tayyip Erdogan said on Thursday Greece should stop arming islands in the Aegean Sea that have a demilitarised status and abide by international agreements, in comments likely to further fuel long-running tensions between the neighbours.
The NATO allies have long been at odds over issues such as maritime boundaries and claims over their respective continental shelves in the Mediterranean Sea, as well as airspace, migrants and ethnically split Cyprus.
Tensions have flared again recently over the Aegean islands, which Ankara says cannot be armed under the 1923 Lausanne and 1947 Paris treaties.
In a speech while observing Turkish military exercises near the Aegean coastal province of Izmir, Erdogan called on Athens to "avoid dreams, acts and statements that will result in regret", and invoked Turkey's independence war in the early 1920s when Turks defeated occupying powers, including Greece.
"Turkey will not renounce its rights in the Aegean and will not back down from using rights that are established by international agreements when it comes to arming islands," Erdogan said.
Last week Erdogan announced Turkey was halting all bilateral talks with Greece over a row with the Greek prime minister, and what Ankara calls airspace violations.
The two had resumed bilateral talks in 2021 on improving ties after a five-year hiatus but have made little progress.
Ankara says the Aegean islands were given to Greece under the 1923 and 1947 treaties on condition that it does not arm them.
Greece has said Turkey's remarks about it arming the islands are "unfounded" and has accused Ankara of questioning its sovereignty over them.
On Thursday Greece's foreign ministry issued 16 maps which it said "depict, in a vivid and unequivocal way, Turkey's illegal, unilateral actions and allegations."
Both countries have sent the United Nations letters outlining their rival positions on airspace and the islands.
Foreign Minister Mevlut Cavusoglu has repeatedly said Turkey would start questioning Greek sovereignty over the islands if Athens persisted in arming them.
Greek government spokesman Giannis Economou, asked about the risks of a possible armed clash, told reporters on Thursday that Athens was handling "a crescendo of inflammatory Turkish statements" with composure.