ATHENS, Greece (AP) — Delegations from Greece and Turkey were meeting in Athens on Monday as part of long-standing efforts to improve often tense relations between the two neighbors, days after Turkey voiced objections over Greece’s plans to create 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.