the Secretary of Defense and the Commissioner of U.S. Customs and Border Protection, may reduce the variable charge to zero for any covered product if the Secretary determines that such product is imported for purposes of fulfilling a contract with— (I) the Department of Defense, or (II) any contractor of the Department of Defense. (ii) Form (I) In general Any reduction under this subparagraph shall only apply to a covered product— (aa) for the period that the contract described in clause (i) is in effect, and (bb) with respect to the quantity of such covered product which is required to fulfill the contract described in such clause. (iii) Publication The Secretary shall make public any reduction under this subparagraph with respect to a covered product unless the publication of such information would negatively affect national security. (B) International partnership agreements In the case of— (i) any upper-middle-income country, or (ii) any country which has entered into a mutual defense treaty or security partnership with the United States, the United States Trade Representative (in consultation with the Secretary of Defense and the Secretary of State) may permit such country to be subject to the requirements applicable to a low-income country or a lower-middle-income country under section 203 of the Foreign Pollution Fee Act of 2023 if completion of an international partnership agreement with such country is determined to assist in the national security or geopolitical positioning of the United States. (4) Free trade agreement In the case of any covered product— (A) which is produced in a country with which the United States has a free trade agreement, (B) for which all of the transforming parts or components parts necessary to produce such covered product are produced within— (i) any country with which the United States has a free trade agreement, or (ii) the United States, and (C) for which the pollution intensity difference is not greater than 50 percent, the variable charge shall be zero. (e) Limitation