52 of the thirtieth instrument of such action, this Convention shall enter into force on the thirtieth day after the date of deposit by such State Party or organization of the relevant instrument or on the date this Convention enters into force pursuant to paragraph 1 of this Article, whichever is later. Article 68. Amendments 1. After the expiry of five years from the entry into force of this Convention, a State Party may propose an amendment and send it to the Secretary-General of the United Nations, who shall thereupon communicate the proposed amendment to the States Parties and to the Conference of the States Parties to the Convention for the purposes of considering and deciding on the proposal. The Conference of the States Parties shall make every effort to achieve consensus on each amendment. If all efforts to achieve consensus have been exhausted and no agreement has been reached, the amendment shall, as a last resort, require for its adoption a two-thirds majority vote of the States Parties. 2. Regional economic integration organizations, in matters within their competence, shall exercise their right to vote under this Article with a number of votes equal to the number of their States Parties. Such organizations shall not exercise their right to vote if their member States exercise theirs and vice versa. 3. An amendment adopted in accordance with paragraph 1 of this Article shall be subject to ratification, acceptance or approval by States Parties. 4. An amendment adopted in accordance with paragraph 1 of this Article shall enter into force in respect of a State Party ninety days after the date of the deposit with the Secretary-General of the United Nations of an instrument of ratification, acceptance or approval of such an amendment. 5. When an amendment enters into force, it shall be binding upon those States Parties which have expressed their consent to be bound by it. Other States Parties shall continue to be bound by the provisions of this Convention or any amendments which they have ratified, accepted or approved earlier. Article 69. Reservations