; (ii) multiple countries; or (iii) a group of countries participating in an international forum such as the Organisation for Economic Co-operation and Development or the Group of Seven (G7). (B) Expansions of ex post congressional-executive international partnership agreements In the case of an international partnership agreement previously approved by Congress under subsection (f), additional countries may be added to the agreement without requiring further approval by Congress if the only changes to the agreement— (i) are the addition of a new country to the agreement; and (ii) do not require alterations to subchapter E of the Internal Revenue Code of 1986, as added by title I. (3) Requirements An international partnership agreement entered into under this title is required to provide for— (A) creation of compatible methods to promote pollution reduction through trade mechanisms by assessing pollution intensity differences between countries; (B) maintenance of the ability of a country that is a party to the agreement to determine methods of pollution reduction within that country; (C) elimination of any fee or charge between countries that are parties to the agreement in a manner compatible to the process described in section 202; (D) elimination or reduction of other duties, import fees, and trade barriers maintained by the country related to covered products; (E) compatible pollution monitoring, reporting, and verification methods that— (i) allow for similar methods to be used to calculate the pollution intensity of covered products and countries that are parties to the agreement, on the basis of the available information within each such country; (ii) allow for similar methods to be used to calculate the pollution intensity of covered products imported from countries that are not parties to the agreement