China is among the first signatories and first parties to the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction, fully demonstrating its responsibility as a major country supporting multilateralism, Foreign Ministry spokesman Lin Jian said on Wednesday.

He made the remarks at a daily news briefing after China deposited with UN Secretary-General Antonio Guterres on Dec 15 an instrument of ratification of the BBNJ Agreement on Tuesday.

The BBNJ Agreement is an important international treaty under the United Nations framework and represents a milestone in international maritime law as it was reached by consensus after 19 years of negotiations involving more than 190 countries, Lin told reporters.

The agreement aims to promote sustainable development of the oceans through the protection of marine ecosystems, guide countries toward a green transition in deep-sea and high-seas activities, and contribute to the implementation of the UN 2030 Agenda for Sustainable Development, Lin said.

"It is of great significance for advancing global ocean governance and safeguarding the international maritime order," he added.

Lin noted that as a major country engaged in deep-sea and high-seas activities, China attaches great importance to marine environmental protection and has participated extensively in the negotiations on the agreement, making important contributions to its conclusion.

According to the spokesman, China signed the agreement on the first day it opened for signature, becoming one of the first signatories, and deposited its instrument of ratification with the UN secretary-general before the agreement entered into force, making it among the first parties.

This will help promote broader participation in the agreement and safeguard the common well-being of humanity, he said.

Lin expressed China's readiness to work with all parties to support the comprehensive, accurate and effective implementation of the agreement, jointly protect and build humanity's blue home, and make unremitting efforts to promote the building of a community with a shared future for humanity.