China calls for safeguarding UNCLOS-based maritime order

China released an assessment report on the United Nations Convention on the Law of the Sea on Tuesday, examining the convention's role and positioning, reviewing its legacy and reaffirming China's commitment to the multilateral maritime order.

Titled Assessment Report on the United Nations Convention on the Law of the Sea: Achievements, Positioning, and Challenges, the report was released by the China Institute for Marine Affairs to mark the 30th anniversary of China becoming a State Party to UNCLOS.

"UNCLOS is a true product of globalization and multilateralism, built on broad consensus," said Zhang Haiwen, a professor at the institute.

Zhang said that, in order to accommodate the interests of all parties, some provisions were intentionally left ambiguous, while issues on which negotiators could not reach agreement were deliberately left unresolved.

She cited marine scientific research as an example. UNCLOS contains a dedicated section on the subject, setting out approval procedures, guiding principles and environmental protection requirements. However, the convention does not define what constitutes marine scientific research because negotiators failed to reach a consensus.

That gap has had practical consequences, Zhang said. She noted that the United States classifies military hydrographic surveys conducted in other countries' exclusive economic zones as distinct from marine scientific research, arguing that such activities do not require prior approval — an interpretation disputed by China and many other countries.

Beyond implementation gaps, the report says UNCLOS also faces new challenges from developments that were beyond the foresight of its drafters, including climate change, artificial intelligence and autonomous vessels.

The BBNJ Agreement, which entered into force this year, illustrates how the international community has sought to update the framework to reflect evolving realities, Zhang said. The agreement establishes rules for conserving and sustainably using marine biodiversity in areas beyond national jurisdiction, a concept that was not recognized during the original UNCLOS negotiations.

While the report says the convention's inherent limitations can be addressed through subsequent State practice and coordinated multilateral action, it warns that external challenges — including distorting the meaning of UNCLOS provisions, abusing its dispute settlement procedures and arbitrarily expanding judicial or arbitral jurisdiction — pose a genuine threat to the legal order established under the convention.

The report also notes that a non-party state invokes customary international law to justify unilateral actions, including delineating the so-called "extended continental shelf" and advancing deep-sea mining by bypassing the governance of the International Seabed Authority.

"UNCLOS designates mineral resources in the international seabed area as the common heritage of humanity, with the ISA managing exploration and exploitation on behalf of all humanity," Zhang said.

She added that negotiations on exploitation regulations have stalled because of a deadlock between environmental advocates calling for a moratorium and contractors asserting what they see as their legal right to proceed.

Against this backdrop, the United States has established a domestic mechanism to issue mining licenses for the international seabed area, inviting companies — including those holding ISA contracts — to register subsidiaries and apply for US-issued permits. This effectively shifts the benefit-sharing obligations under the ISA system into tax payments to the United States, Zhang said.

The move amounts to substituting domestic law for international law, she said, calling it "a very bad precedent that seriously undermines the convention's authority and the balance of interests it was designed to protect."