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Timor-Leste seeks permanent maritime boundaries with its neighbours, Indonesia and Australia. Timor-Leste and Indonesia have commenced talks on permanent maritime boundaries pursuant to international law, in particular United Nations Convention on the Law of the Sea (UNCLOS).

In March 2002, two months before Timor-Leste’s restoration of independence, Australia ‘carved-out’ maritime boundary disputes from the binding jurisdiction of the international dispute resolution bodies. This carve-out remains today and means that Timor-Leste is not able to seek a binding determination of its maritime boundaries with Australia from an international court or tribunal without Australia’s agreement. While revenue-sharing agreements between Timor-Leste and Australia exist in relation to the Timor Sea, there is no permanent maritime boundary.

This section focuses on the key principles of the international law of the sea and how international courts determine maritime boundaries, the current arrangements, negotiations with Indonesia, as well as the historical, recent and current issues between Australia and Timor-Leste.

Maritime boundary

Coastal States are entitled to define or ‘delimit’ the extent of their sovereign maritime territory in accordance with international law. The United Nations Convention on the Law of the Sea recognises different kinds of rights to maritime areas, such as the territorial sea (close to the coastline), the Exclusive Economic Zone (which extends up to 200 nautical miles from the coastline), and the continental shelf (which can underlie the Exclusive Economic Zone or extend beyond the Exclusive Economic Zone in certain circumstances). Each State will exercise sovereign rights from its coast up to its maritime boundary.


United Nations Convention on the Law of the Sea (UNCLOS)

The main international agreement relating to the law of the sea. The United Nations Convention on the Law of the Sea was finalised in 1982 and has been in force since 1994. The United Nations Convention on the Law of the Sea is one of the most signed (and ratified) international treaties in the world.


To learn more about the 1982 United Nations Convention on the Law of the Sea, including a brief history of the development of international maritime boundary law, the key concepts under the 1982 Convention and the accepted approach to delimitation of maritime boundaries, click here

To learn more about the Timor Sea Agreements, and why they do not constitute a permanent maritime boundary, click here

To learn more about the past and current legal issues between Australia and Timor-Leste, click here

To learn about Timor-Leste and Indonesia’s recent talks on maritime boundaries, click here

For Frequently Asked Questions, click here

For copies of all relevant Timor Sea treaties, recent articles and further resources on Timor-Leste and international maritime boundary law, click here