Nothing in this section or the Trade Expansion Act of 1962 [
19 U.S.C.
1801 et seq.] shall be construed to prevent the application, with respect to rates of duty established under this section or the Trade Expansion Act of 1962 pursuant to agreements with countries other than Cuba, of the provisions of the treaty of commercial reciprocity concluded between the United States and the Republic of Cuba on December 11, 1902, or to preclude giving effect to an agreement with Cuba concluded under this section or the Trade Expansion Act of 1962, modifying the existing preferential customs treatment of any article the growth, produce, or manufacture of Cuba. Nothing in this chapter or the Trade Expansion Act of 1962 shall be construed to preclude the application to any product of Cuba (including products preferentially free of duty) of a rate of duty not higher than the rate applicable to the like products of other foreign countries (except the Philippines), whether or not the application of such rate involves any preferential customs treatment. No rate of duty on products of Cuba shall be decreased—