/əˈdɪʃənl ˈproʊtəˌkɒl/ – Phrase
Definition: nghị định thư bổ sung, biên bản bổ sung.
A more thorough explanation: An additional protocol is a formal agreement that supplements and adds to an existing treaty or international agreement. It may clarify certain provisions, expand the scope of the original agreement, or introduce new obligations or procedures. Additional protocols are typically negotiated and adopted by the parties to the original agreement and are considered legally binding upon ratification or acceptance.
Example: The parties agreed to sign an additional protocol to the treaty in order to clarify certain provisions.