Tension rises as regional rivals Turkey, Greece voice festering grievances

Troubled relations between regional rivals Turkey and Greece have worsened, with Turkey's president doubling down on a thinly veiled invasion threat and Athens responding that it's ready to defend its sovereignty.

Turkey and Greece have decades-old disputes over an array of issues, including territorial claims in the Aegean Sea and disagreements over the airspace there.

The friction between the neighbours has brought the NATO allies to the brink of war three times in the last half-century.

Turkish President Recep Tayyip Erdogan said Turkey could come all of a sudden one night in response to perceived Greek threats, suggesting a Turkish attack on its neighbour cannot be ruled out.

Questioned about his earlier use of the phrase over the weekend and the possibility of Turkish military action, Erdogan reiterated the expression.

What I'm talking about is not a dream, he said at a news conference in the Bosnian capital Sarajevo.

If what I said was that we could come one night all of a sudden (it means) that, when the time comes, we can come suddenly one night.

Greek Foreign Minister Nikos Dendias said that for days Turkish officials have been making outrageous comments against Greece, including Erdogan's remarks that he said suggested Turkey could invade the Greek islands.

I would advise anybody who dreams of attacks and conquest to consider three or four times, he said after talks in Athens with French Foreign Minister Catherine Colonna.

We are in a position to defend our country, our independence and territorial integrity.

Ankara says Greece is violating international agreements by militarising islands close to Turkey's Aegean coastline. It has also accused Greek air defenses of locking on to Turkish fighter jets during NATO exercises over the eastern Mediterranean.

Dendias said Greece needs to defend its eastern Aegean Sea islands including tourist hotspots Rhodes and Kos, which are much closer to Turkey than to the Greek mainland against its larger and militarily stronger neighbor.

The Turkish side maintains that these islands are under Greek occupation, he said.

Let me point out that opposite the Aegean islands is stationed the biggest landing fleet in Europe and a full Turkish army group, he said.

He also accused Turkey's military of repeatedly violating Greek airspace and waters.

This year there have been 6,100 violations of our airspace, 157 overflights of Greek territory and 1,000 violations of our territorial waters, he said.

Greece almost daily scrambles fighter aircraft to identify and intercept Turkish military planes and often simulated dogfights break out, which have led to several fatalities in the past decades.

Erdogan was no less adamant. There are some illegitimate threats against us and if these illegitimate threats continue there's an end to one's patience, he said.

When the time is due, necessary action will be taken because it is not a good sign to lock on radars to our planes. Such things done by Greece are not a good sign.

Erdogan has previously said Turkish forces can come all of a sudden one night when threatening military action against Kurdish militants in Syria and Iraq. Turkey has conducted several military operations against the militants in recent years.

He first used the phrase in connection to Greece at an aerial technology festival on Saturday.

Erdogan faces elections next year, as does Greek Prime Minister Kyriakos Mitsotakis, and increasing rhetoric against Greece would rally his nationalist base amid Turkey's economic troubles.