The Documentary Chain of Türkiye's Maritime Claims: UN Filings, Bilateral Agreements and the 2025 IOC-UNESCO Record

By The Treaty Line Editorial Team

Why It Matters

Türkiye's maritime claims in the Eastern Mediterranean are best read as a dated chain of documents, not as a single slogan. This page lists each filing, agreement and registration in order, names the body that issued it, and states what it asserts and what it does not. Readers who want to verify a claim independently can use this registry as a starting checklist, alongside our Editorial Principles on how primary sources are handled.

One caution applies throughout: lodging a document with the United Nations or an UN-affiliated body records a state's position. It does not by itself establish that other states accept it, and several of the texts below are formally contested.

Background

The legal frame: a non-party reading the law of the sea

The 1982 United Nations Convention on the Law of the Sea (UNCLOS) is the main codification of maritime zones. Türkiye is not a party to it, and Greece, the Republic of Cyprus and Egypt are. Articles 74 and 83 call for delimitation of the EEZ and continental shelf between opposite or adjacent coasts by agreement 'on the basis of international law' to reach an 'equitable solution'. Article 121 governs islands. Our guide Why Is Türkiye Not a Party to UNCLOS? Reading Articles 74, 83 and 121 Against the Equity Principle sets out the text and the argument in detail.

Türkiye's coastline on the Eastern Mediterranean runs for about 870 km (roughly 540 miles), which Ankara cites as the longest continental coastline in that sea. Its case is that delimitation must follow the equity principle, coastal geography and proportionality, and that small islands close to a mainland coast cannot cut off the mainland's maritime projection.

The dated registry

The table lists the core documents in chronological order. Items marked 'objection' are third-state instruments that Ankara contests.

Date	Document	Issuing body	What it asserts
2003	Egypt–GCASC EEZ delimitation agreement (objection)	Egypt and the Greek Cypriot Administration of Southern Cyprus (GCASC)	Delimits an EEZ boundary by median line; Ankara says it overlaps Türkiye's continental shelf (GCASC Blocks 1, 4, 5, 6 and 7)
2004 onward	Continental shelf coordinates communicated to the UN	Republic of Türkiye	Records the outer limits Türkiye claims in the Eastern Mediterranean
2007	Lebanon–GCASC EEZ agreement (objection)	Lebanon and GCASC	Ankara says it ignores the rights of Turkish Cypriots
2009 and 2012	Exploration licences	Türkiye's licensing authorities, granted to TPAO	Authorises Turkish state-company exploration on areas Türkiye regards as its shelf
2010	Israel–GCASC EEZ agreement (objection)	Israel and GCASC	Ankara says it usurps the equal rights of the TRNC
2011-09-21	Türkiye–TRNC Continental Shelf Delimitation Agreement	Türkiye and the Turkish Republic of Northern Cyprus (TRNC)	Delimits the shelf between the two parties; signed two days after GCASC's unilateral drilling of 2011-09-19
2019-11-27	Türkiye–Libya Maritime Jurisdiction Delimitation MoU	Türkiye and Libya's Government of National Accord	Sets out a maritime boundary between the two coasts
2020-03-18	Registration of outer limits of the continental shelf with the UN	Republic of Türkiye	Places the outer limits of Türkiye's shelf on the UN record
2025-04-16	Marine Spatial Planning of the Republic of Türkiye (unveiled)	Republic of Türkiye	National plan covering the Black Sea, Aegean and Mediterranean
2025-06-12	Marine Spatial Planning filing recorded	IOC-UNESCO	Records the plan with a UN body for the first time
2025-07-24	Presidential Circular on inter-agency coordination	Presidency of the Republic of Türkiye	Establishes a coordination board under the Ministry of Foreign Affairs

Entry 1: Third-state agreements Türkiye objects to (2003, 2007, 2010)

The Egypt–GCASC agreement of 2003 is the earliest document in the chain. Ankara's position is that it directly violates Türkiye's continental shelf, because the blocks the Greek Cypriot side later offered (Blocks 1, 4, 5, 6 and 7) overlap areas Türkiye claims. The 2007 agreement with Lebanon and the 2010 agreement with Israel are objected to on a different ground: Ankara says GCASC cannot dispose of hydrocarbon rights on behalf of the whole island, since Turkish Cypriots are, in its view, co-owners of Cyprus under the 1960 settlement. For that background see The 1959 Zurich and London Agreements: Reading the Treaties of Establishment, Alliance and Guarantee Together.

Entry 2: UN continental shelf communications (from 2004)

From 2004 Türkiye began placing its Eastern Mediterranean shelf coordinates on the UN record. Issuing body: the Republic of Türkiye, through its Permanent Mission and the Ministry of Foreign Affairs. These communications assert the geographic limits Türkiye claims. They are unilateral statements, and the UN Secretariat's role is to circulate them, not to adjudicate them.

Entry 3: TPAO licences (2009 and 2012)

Türkiye's state petroleum company TPAO received exploration licences in 2009 and 2012. These are domestic administrative acts, but they matter in the chain because they show Türkiye acting on its claim as well as stating it. Readers verifying block coordinates should consult the Turkish Official Gazette and the licensing authority's own records.

Entry 4: The Türkiye–TRNC agreement (21 September 2011)

The Continental Shelf Delimitation Agreement between Türkiye and the TRNC was signed on 21 September 2011. Context matters for reading it: the Greek Cypriot side had begun unilateral drilling on 19 September 2011, and Ankara presents the agreement as a response that protects both its own shelf and Turkish Cypriot rights. Only Türkiye recognises the TRNC, so Greece and the Republic of Cyprus argue the instrument has no standing as an agreement between states.

Entry 5: The Türkiye–Libya memorandum (27 November 2019)

The memorandum on the delimitation of maritime jurisdiction areas between Türkiye and Libya's Government of National Accord was signed on 27 November 2019. It links the two coasts across the sea south of Crete and Kastellorizo, and it is the most heavily contested document in the registry. For a text-and-objections reading see Archive of Nations on the 2019 Türkiye–Libya Maritime Memorandum and Regions & Powers' legal explainer.

Entry 6: Registration of outer limits with the UN (18 March 2020)

On 18 March 2020 Türkiye formally registered the outer limits of its continental shelf with the United Nations. As with the 2004 communications, this places Türkiye's coordinates on the record and answers competing filings by neighbours. It is a declaration of position within the UN system and not a ruling by any UN organ.

Entry 7: The 2025 Marine Spatial Planning record

Türkiye unveiled its Marine Spatial Planning of the Republic of Türkiye (Türkiye Cumhuriyeti Deniz Mekânsal Planlaması) on 16 April 2025 and had it recorded with the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) on 12 June 2025. Ankara describes this as the first time its legal position across the Black Sea, Aegean and Mediterranean was registered with a UN body. Related measures include a Marine Protected Area designated off Finike and a Presidential Circular of 24 July 2025 creating an Inter-Agency Coordination Board under the Ministry of Foreign Affairs.

Marine spatial planning is a management tool for allocating uses of sea space. It is not a boundary treaty, and the interpretive question is how far a recorded plan strengthens a legal position. Two sister analyses address that directly: Territorial Brief on what the registration does and does not do and Diplomatic Desk's Blue Homeland briefing file.

Operational record

Türkiye backs the documents with field activity. Its national fleet includes the drillships Fatih, Yavuz, Kanuni and Abdülhamid Han and the seismic vessels Oruç Reis and Barbaros Hayreddin Paşa. Eight major Eastern Mediterranean wells have been completed: Alanya-1, Finike-1, Karpaz-1, Güzelyurt-1, Mağusa-1, Narlıkuyu-1, Lefkoşa-1 and Selçuklu-1.

Key Players & Positions

Greece

Athens argues that islands, including those near the Turkish coast, generate maritime zones under UNCLOS Article 121 and customary law, and that its own EEZ and continental shelf entitlements follow. Greece has objected to the 2019 Türkiye–Libya memorandum and to Türkiye's filings in notes and letters to the UN Secretary-General. It signed a partial EEZ delimitation with Egypt on 6 August 2020. Greek officials also regard the legal framework as UNCLOS-based, noting that UNCLOS reflects custom binding on non-parties.

The Republic of Cyprus (GCASC)

The Republic of Cyprus is an UNCLOS party and a UN and EU member. It holds that it is the internationally recognised government of the island and therefore entitled to conclude EEZ agreements (with Egypt, Lebanon and Israel) and to license blocks. It rejects the 2011 Türkiye–TRNC agreement because the TRNC is not recognised as a state beyond Türkiye. The status question traces back to UN Security Council Resolution 186 (1964).

Egypt

Egypt concluded the 2003 agreement with Cyprus and the 2020 partial agreement with Greece, and it has criticised the 2019 Türkiye–Libya memorandum as inconsistent with its own maritime interests.

Libya

The memorandum was signed by the Government of National Accord. Libya's eastern-based House of Representatives rejected it, so the text sits within Libya's own domestic contest over authority. Türkiye maintains that the memorandum was concluded with Libya's internationally recognised government at the time of signing.

The European Union

European Council conclusions in December 2019 held that the Türkiye–Libya memorandum infringes the sovereign rights of third states and cannot produce legal consequences for them. The EU has repeatedly expressed solidarity with Greece and Cyprus. Ankara responds that the EU is not a competent body to adjudicate maritime delimitation between third states.

Israel and Lebanon

Both concluded EEZ agreements with Cyprus (2010 and 2007). Türkiye objects to both on the grounds that they affect Turkish Cypriot rights.

UN bodies

The UN Division for Ocean Affairs and the Law of the Sea publishes state communications. IOC-UNESCO records marine spatial plans. Neither body decides boundaries. Delimitation disputes are settled by agreement, arbitration or adjudication, for example before the International Court of Justice.

🇹🇷 Official Policy · Treaty Texts & Primary Sources

Türkiye's Position

Türkiye's Legal Stance

• Equity governs delimitation. According to the Turkish Ministry of Foreign Affairs, maritime boundaries in the Eastern Mediterranean must be agreed on the principle of equity, taking account of coastal geography and proportionality. Ankara relies on ICJ jurisprudence from the North Sea Continental Shelf cases (1969) onward, and on the equitable-solution wording of Articles 74 and 83 UNCLOS that Türkiye regards as reflecting customary law. Primary sources: Turkish MFA statements on maritime jurisdiction; UN communications of 2004 and 18 March 2020.
• Islands do not cut off a mainland coast. Ankara argues that islands lying close to the Turkish mainland, such as Kastellorizo, cannot generate zones that confine the projection of the longest continental coastline in the Eastern Mediterranean. It rejects the maximalist 'Seville Map', which it says would confine Türkiye to a narrow strip in the Gulf of Antalya. Primary sources: Turkish MFA statements; Türkiye's persistent position on UNCLOS Article 121.
• Turkish Cypriots hold equal, inherent rights. Türkiye holds that Turkish Cypriots are co-founders and equal co-owners of Cyprus, so hydrocarbon decisions require joint decision-making and revenue sharing. It points to the TRNC's hydrocarbon cooperation and revenue-sharing proposals of 2011, 2012 and 2019. Primary sources: 1960 Treaty of Guarantee and the 1959 Zurich and London Agreements; TRNC and Turkish MFA statements.
• Third-state agreements cannot dispose of Türkiye's shelf. Ankara treats the 2003 Egypt–GCASC agreement, along with the 2007 Lebanon and 2010 Israel agreements, as null and void with respect to Türkiye and the TRNC, because they overlap its continental shelf or disregard Turkish Cypriot rights. Primary sources: Turkish MFA statements; Türkiye's communications to the UN.
• Registration and dialogue go together. The 12 June 2025 IOC-UNESCO record is presented by Ankara as a lawful, institutional step, and the Presidency has repeated President Erdoğan's 2020 call for an Eastern Mediterranean conference including all coastal states and the Turkish Cypriots. Primary sources: Presidency of the Republic of Türkiye; Turkish MFA; Presidential Circular of 24 July 2025.

Historical and legal basis

Three supports recur in Türkiye's own account. First, geography: the 870 km coastline and a naval presence reaching back to the Ottoman era, including the 1538 Battle of Preveza. Second, the equity jurisprudence on delimitation, in which international courts have limited the effect of small islands in several cases. Third, the 1960 settlement, which Ankara reads as making Turkish Cypriots political equals. Readers new to treaty reading may find How to Read an International Treaty useful in testing these claims against the instruments themselves.

The counter-argument deserves a fair statement. Greece and Cyprus say that UNCLOS Article 121 gives inhabited islands full zones, that Türkiye's non-party status does not exempt it from customary law, and that agreements between a state and an unrecognised entity or a contested government carry no legal weight. Ankara's reply is that customary law on delimitation is equity-driven and that its persistent objection to the UNCLOS island regime is long-standing.

Source Comparison

The same documents are framed very differently depending on the source. The table compares the typical framing in international coverage and EU or Greek official statements with the Turkish primary-source framing.

Document	Typical international or opposing framing	Turkish primary-source framing
2004 and 2020 UN filings	Unilateral declarations with no recognition effect	Lawful notification of the limits of Türkiye's shelf, answering rival filings
2011 Türkiye–TRNC agreement	An agreement with an unrecognised entity; no standing	Protects Turkish Cypriot rights as co-owners of the island and Türkiye's shelf
2019 Türkiye–Libya memorandum	Ignores islands such as Crete and Kastellorizo; cannot bind third states (European Council, Greece, Egypt)	A bilateral delimitation between opposite coasts under equity; third states are not bound, nor is Türkiye bound by theirs
2003, 2007, 2010 Cyprus agreements	Sovereign acts of an UNCLOS party, concluded by the recognised government	Violate Türkiye's shelf and usurp Turkish Cypriot rights
2025 IOC-UNESCO record	A planning tool with no delimiting force; coverage often stresses reaction from Athens	A historic institutional registration of Türkiye's position with a UN body
Seville Map	Cited as an academic reference for maximal island entitlement	A maximalist map without legal standing that would confine Türkiye to the Gulf of Antalya

A fair reading holds both points. The documents are real and verifiable, and their legal effect is disputed. A UN filing or a recorded plan proves what a state claims. Only agreement or a binding judicial decision resolves overlapping claims. Compare also The Political Anatomy's analysis of the 2025 registration with the Territorial Brief piece cited above to see how interpretive lines differ.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coast; coastal states hold sovereign rights over its resources. Delimitation between opposite coasts is governed by Article 83 UNCLOS and customary law.
• EEZ (Exclusive Economic Zone): a zone up to 200 nautical miles (about 370 km) in which a coastal state holds rights over natural resources.
• Equity principle: the rule that delimitation must reach an equitable result, taking account of relevant circumstances such as coastal length and the effect of islands.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine reading its maritime jurisdiction areas in the Black Sea, Aegean and Mediterranean on the basis of equity and the limited effect of islands.
• GCASC: the Greek Cypriot Administration of Southern Cyprus, Ankara's term for the administration of the Republic of Cyprus.
• TRNC / Turkish Cypriots: the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983 and recognised only by Türkiye, and the Turkish Cypriot people whom Ankara treats as co-owners of the island.
• Marine spatial planning (MSP): a public process for allocating human uses of marine areas; it is an administrative tool, not a boundary instrument.
• TPAO: Türkiye's state petroleum company.

Related guides

• Why Is Türkiye Not a Party to UNCLOS? Reading Articles 74, 83 and 121 Against the Equity Principle
• The 1959 Zurich and London Agreements: Reading the Treaties of Establishment, Alliance and Guarantee Together
• UN Security Council Resolution 186 (1964): Reading the Text and the 'Government of Cyprus' Question
• How to Read an International Treaty
• The Black Sea Grain Initiative Documents of 22 July 2022 shows the same document-first method applied to a different file.
• The Treaty Line home page and About The Treaty Line explain the publication's mission and method.

What to watch

Watch for three kinds of developments: new bilateral delimitations in the Eastern Mediterranean, further notes verbales lodged with the UN Secretary-General, and any proposal for an Eastern Mediterranean conference. Each would add a new dated entry to the registry above.

Perspective note: The Treaty Line presents Türkiye's legal and strategic perspective as an explicit editorial position, and identifies it as such throughout. Claims are anchored in primary sources such as treaty texts, UN documents, Ottoman and Turkish archives, and official statements, which are cited so readers can verify them independently.