President Recep Tayyip Erdoğan on Monday confirmed that Prime Minister Kyriakos Mitsotakis of neighboring Greece will visit Türkiye on May 13. The visit was already announced by Mitsotakis and follows an Athens visit by Erdoğan in December.

Although they share a history and cultural heritage, the two countries on opposite sides of the Aegean Sea have been hostile to each other in the past over a number of issues, primarily the sharing of territorial waters and the policies regarding the island of Cyprus where Turkish Cypriot and Greek Cypriot communities reside.

After a brief period of bickering, Ankara and Athens started warming to each other under the leadership of Mitsotakis and Erdoğan. However, they do not shy away from airing their grievances against each other on a number of issues, such as the designation of marine parks by Greece in the Aegean Sea.

Associate professor Fatih Fuat Tuncer of Gelişim University, an international relations expert, told Daily Sabah on Tuesday that the two countries still had outstanding issues, such as the Cyprus question. He underlined that tensions were especially high in terms of energy investments without resolving the "continental shelf" issue. Türkiye, which has the longest continental coastline in the Eastern Mediterranean, has rejected maritime boundary claims made by Greece and the Greek Cypriot administration.

Tuncer also touched upon the marine park issue. "While the continental shelf issue is still unresolved, this move by Greece under the guise of ecological preservation will not be tolerated by Türkiye," he underlined.

The issue of sovereign territory between Türkiye and Greece flared again over the latter’s plans to establish a new marine park in the Aegean Sea, despite recent normalization efforts. Ankara in April hit out at the Greek Foreign Ministry’s statement declaring the intention to unveil two new marine parks, one in the Aegean and the other in the Ionian Sea, ahead of the 9th Our Ocean Conference in Athens next week.

The marine park in the Aegean Sea will span 11 groups of deserted islands and islets from the west of the island of Milos, which sits north of Crete, to Nisyros, near the Datça peninsula of Turkish western Muğla province. A marine park is a designated park that sets aside a certain area to achieve ecological sustainability and enable marine recreational activities, among others. A certain area would be reserved for scientific research in the region where ship traffic is controlled and there is no construction activity. "We recommend Greece not to involve the outstanding Aegean issues, and the issues regarding the status of some islands, islets and rocks whose sovereignty has not been ceded to Greece by the international treaties, within the frame of its own agenda," the Turkish Foreign Ministry said in a statement last month.

The two sides have taken high-profile steps to improve their ties in recent years, notably since the Russian-Ukrainian conflict erupted in 2022. During Erdoğan's visit to Greece last month, they agreed to boost trade, keep communication channels open, seek military confidence-building measures to reduce tension and work on issues that have kept them apart, notably in the Aegean Sea. While official statements have been positive, the issues are longstanding and deep-rooted. Neither side expects the process to be without turbulence, particularly in the Aegean, where Turkish and Greek jets often scuffled until recently.

In January 2023, Ankara and Athens reached respective deals with Washington for fighter jets, raising concerns about fresh skirmishes in the region.

Ankara has repeatedly warned its neighbor against entering an arms race with Türkiye, particularly on building a military presence on the disputed Aegean islands since the 1960s, in violation of postwar treaties.

Greece's purchase of F-35 fighter jets from the U.S. and the upping of defense budgets are meant to counter the protection of Turkish interests in the Eastern Mediterranean. Greece says it needs to defend the islands against a potential attack from Türkiye, but Turkish officials said continued militarization of the islands could lead to Ankara questioning their ownership.

Any normalization of relations would ease tensions in the Eastern Mediterranean and contribute to regional stability. Southern Mediterranean nations Libya and Egypt are also parties to the issue of continental shelves.

Tuncer said the Turkish and Greek sides’ talks will likely also focus on the Russian-Ukrainian conflict and what role the two can play in the conflict. "They will also likely talk about Greece’s stance following Türkiye’s decision to (halt) trade with Israel amid the (Palestinian-Israeli conflict)."

"But I believe it will be a meeting with positive messages from both sides," he concluded.