Turkish and Greek delegations met in Athens on Monday as part of long-standing efforts to improve often tense relations between the rival nations days after Türkiye objected to Greece’s plans to build marine nature reserves in the Ionian and Aegean seas.

The two regional rivals are NATO allies but have been at odds for decades over a series of issues, including territorial claims in the Aegean and drilling rights in the Mediterranean, and have come to the brink of war three times in the last 50 years. A dispute over energy exploration rights in 2020 led to the two countries' warships facing off in the Mediterranean.

Monday’s meeting in the Defense Ministry in Athens was to discuss confidence-building measures, following a similar meeting in Ankara last November. The two countries have engaged in the confidence-building process on and off for years, trying to seek common ground on a series of lower-key issues as a means of improving ties.

The meeting comes ahead of planned talks in Ankara on May 13 between President Recep Tayyip Erdoğan and Greek Prime Minister Kyriakos Mitsotakis.

Tense ties have improved significantly over the past year, with Erdoğan visiting Athens in December and signing a raft of trade, energy and education deals.

But Mitsotakis’ announcement last week that Greece will create two marine parks for the protection of sea mammals and birds – one in the Ionian Sea in western Greece and one in the central Aegean – has angered Türkiye.

Ömer Çelik, spokesperson for Erdoğan’s ruling Justice and Development Party (AK Party), said last week that Ankara considers the plan "a step that sabotages the normalization process" in relations, and said Türkiye would "in no way allow actions toward the declaration of marine parks in the Aegean Sea."

Mitsotakis, speaking last week after a meeting of European leaders in Brussels, expressed surprise at what he described as "Türkiye’s totally unjustified reaction to an initiative which at the end of the day is of an environmental nature."

The Greek prime minister said the recent improvement in relations between Greece and Türkiye was "undeniable and measurable," but that this did not mean Türkiye had changed its positions on the delineation of maritime zones in the Aegean and the Eastern Mediterranean.

"These positions remain positions which are deeply problematic for our country," Mitsotakis said.

"But this does not prevent us from being able to talk, to create a general good climate and invest more in a positive agenda and less in the issues which divide us and over which we clearly disagree."

Türkiye’s delegation at Monday’s talks was led by Deputy Foreign Minister Burak Akçapar, while the Greek one was headed by Ambassador Theocharis Lalakos, Greece’s Defense Ministry said.