A treaty may be amended by the agreement of the Parties. Every Party to a treaty is entitled to participate in the amendment’s negotiations and to become a Party to the new amendment.
Parties are not required to adopt amendments. In fact, in
accordance with the Vienna Convention on the Law of
Treaties (part IV), the pre-amendment terms remain binding
for any Party that does not adopt the amendment, even in
dealings with a Party that is bound by the amendment.
Article 14 concerns amendments to the Convention and to
annexes: who can propose them
(para. 1), the process for
submission (para. 2), how they are to be adopted (para. 3)
how they enter
into force (paras. 4, 5 and 6).
For a more detailed description of the amendment procedure,see the Implementation Guide to the Convention, pages 146-147.