Vietnam and Indonesia Sign Maritime Boundary Agreement After 14 Years

Exclusive Economic Zone Delimitation Ends Longstanding Dispute

Vietnam and Indonesia signed a maritime boundary agreement on January 27, 2026, in Hanoi, delimiting their overlapping exclusive economic zones in the South China Sea after 14 years of negotiations. The agreement establishes a boundary line through the Natuna Sea, resolving conflicting claims over approximately 98,000 square kilometers of maritime space rich in fisheries and potential hydrocarbon resources.

Vietnamese Foreign Minister Bui Thanh Son and Indonesian Foreign Minister Retno Marsudi signed the agreement in the presence of Vietnamese President Luong Cuong and Indonesian President Prabowo Subianto. "This agreement demonstrates that ASEAN nations can resolve maritime disputes peacefully through dialogue and international law," Retno said.

Boundary Details

The negotiated boundary follows a modified equidistance line adjusted for the geographic configuration of Vietnam's Con Dao islands and Indonesia's Natuna Islands. Vietnam made concessions on its initial claim near the Natuna area, while Indonesia accepted a boundary that gives Vietnam access to fishing grounds its fleet has traditionally used.

The agreement includes provisions for joint development of hydrocarbon resources in a 12,000-square-kilometer zone where the two countries' continental shelf claims overlap. A joint management authority will oversee exploration licensing, with revenue shared 50-50.

Fisheries Management

A supplementary fisheries agreement grants Vietnamese fishing vessels a three-year transitional access period to waters that now fall under Indonesian jurisdiction, during which vessel numbers will be gradually reduced. Indonesia had previously arrested hundreds of Vietnamese fishing boats for illegal fishing in the Natuna area, a persistent irritant in bilateral relations.

The Indonesian Ministry of Marine Affairs estimated that illegal fishing in the Natuna Sea caused losses of $4.2 billion annually, though the figures include fishing by all foreign vessels, not only Vietnamese. The agreement establishes a joint patrol mechanism and a hotline between coast guard agencies to manage fishing incidents.

Strategic Implications

The agreement is significant in the context of the South China Sea disputes, as it demonstrates that claimant states can resolve overlapping claims bilaterally using the United Nations Convention on the Law of the Sea framework. Both countries emphasized that the agreement was "without prejudice" to their respective positions on other South China Sea claims.

Nguyen Hong Thao, a member of the UN International Law Commission and professor at Vietnam National University, said the deal "sets a positive precedent that could encourage similar negotiations between other ASEAN claimant states." The Philippines and Vietnam have discussed EEZ delimitation but negotiations remain at an early stage.