Sea-level rise (SLR) is considered one of the most serious consequences of climate change. The risk of SLR compels legal consideration of this phenomenon related to many interrelated domains including the Law of the Sea. The Western Pacific region contains the most low-lying coastal countries and small island States seriously affected by SLR in the world. This research has been carried out as a contribution paper on the State practice in the Western Pacific region to the topic of “Sea-level rise in relation to international law” conducted by the Study Group of the United Nations International Law Commission in the period of 2020-2021. It aims to summarize the consequences of SLR for the Western Pacific States and outline their legal positions in relation to the sea-level rise. It also discusses specific issues, challenges and opportunities facing the Western Pacific States in supporting the maintenance of maritime baselines and limits notwithstanding physical changes caused by SLR.

1. Introduction
2. Sea-Level Rise and Actions of the Western Pacific States
3. Legal Base for Maintaining Maritime Baselines andBoundaries in the Face of SLR
    A. Interpretation of the UNCLOS
    B. Fundamental Change of Circumstances
    C. The Land Dominates the Sea Principle
    D. Regular Review
4. Conclusion

• Nguyen Hong Thao(Vice Chairman of the United Nations International Law Commission)