In the event of an amendment to the Statute of the Agency being adopted in accordance with article XVIII–C of the Statute to which the Senate by formal vote shall refuse its advice and consent, upon notification by the Senate to the President of such refusal to advise and consent, all further authority under section ¹ 2021, 2022, 2023 and 2024 of this title, as amended, shall terminate: Provided, however, That the Secretary of State, under such regulations as the President shall promulgate, shall have the necessary authority to complete the prompt and orderly settlement of obligations and commitments to the Agency already incurred and pay salaries, allowances, travel expenses, and other expenses required for a prompt and orderly termination of United States participation in the Agency: And provided further, That the representative and the deputy representative of the United States to the Agency, and such other officers or employees representing the United States in the Agency, under such regulations as the President shall promulgate, shall retain their authority under this chapter for such time as may be necessary to complete the settlement of matters arising out of the United States participation in the Agency.