(a) Additional duties
The President when he finds that the public interest will be served shall by proclamation specify and declare new or additional duties as hereinafter provided upon articles wholly or in part the growth or product of, or imported in a vessel of, any foreign country whenever he shall find as a fact that such country—

(1) Imposes, directly or indirectly, upon the disposition in or transportation in transit through or reexportation from such country of any article wholly or in part the growth or product of the United States any unreasonable charge, exaction, regulation, or limitation which is not equally enforced upon the like articles of every foreign country; or

(2) Discriminates in fact against the commerce of the United States, directly or indirectly, by law or administrative regulation or practice, by or in respect to any customs, tonnage, or port duty, fee, charge, exaction, classification, regulation, condition, restriction, or prohibition, in such manner as to place the commerce of the United States at a disadvantage compared with the commerce of any foreign country.

(b) Exclusion from importation
If at any time the President shall find it to be a fact that any foreign country has not only discriminated against the commerce of the United States, as aforesaid, but has, after the issuance of a proclamation as authorized in subdivision (a) of this section, maintained or increased its said discriminations against the commerce of the United States, the President is authorized, if he deems it consistent with the interests of the United States, to issue a further proclamation directing that such products of said country or such articles imported in its vessels as he shall deem consistent with the public interests shall be excluded from importation into the United States.

(c) Application of proclamation
Any proclamation issued by the President under the authority of this section shall, if he deems it consistent with the interests of the United States, extend to the whole of any foreign country or may be confined to any subdivision or subdivisions thereof; and the President shall, whenever he deems the public interests require, suspend, revoke, supplement, or amend any such proclamation.

(d) Duties to offset commercial disadvantages
Whenever the President shall find as a fact that any foreign country places any burden or disadvantage upon the commerce of the United States by any of the unequal impositions or discriminations aforesaid, he shall, when he finds that the public interest will be served thereby, by proclamation specify and declare such new or additional rate or rates of duty as he shall determine will offset such burden or disadvantage, not to exceed 50 per centum ad valorem or its equivalent, on any products of, or on articles imported in a vessel of, such foreign country; and thirty days after the date of such proclamation there shall be levied, collected, and paid upon the articles enumerated in such proclamation when imported into the United States from such foreign country such new or additional rate or rates of duty; or, in case of articles declared subject to exclusion from importation into the United States under the provisions of subdivision (b) of this section, such articles shall be excluded from importation.

(e) Duties to offset benefits to third country
Whenever the President shall find as a fact that any foreign country imposes any unequal imposition or discrimination as aforesaid upon the commerce of the United States, or that any benefits accrue or are likely to accrue to any industry in any foreign country by reason of any such imposition or discrimination imposed by any foreign country other than the foreign country in which such industry is located, and whenever the President shall determine that any new or additional rate or rates of duty or any prohibition hereinbefore provided for do not effectively remove such imposition or discrimination and that any benefits from any such imposition or discrimination accrue or are likely to accrue to any industry in any foreign country, he shall, when he finds that the public interest will be served thereby, by proclamation specify and declare such new or additional rate or rates of duty upon the articles wholly or in part the growth or product of any such industry as he shall determine will offset such benefits, not to exceed 50 per centum ad valorem or its equivalent, upon importation from any foreign country into the United States of such articles; and on and after thirty days after the date of any such proclamation such new or additional rate or rates of duty so specified and declared in such proclamation shall be levied, collected, and paid upon such articles.

(f) Forfeiture of articles
All articles imported contrary to the provisions of this section shall be forfeited to the United States and shall be liable to be seized, prosecuted, and condemned in like manner and under the same regulations, restrictions, and provisions as may from time to time be established for the recovery, collection, distribution, and remission of forfeitures to the United States by the several revenue laws. Whenever the provisions of this chapter shall be applicable to importations into the United States of articles wholly or in part the growth or product of any foreign country, they shall be applicable thereto whether such articles are imported directly or indirectly.

(g) Ascertainment by Commission of discriminations
It shall be the duty of the commission to ascertain and at all times to be informed whether any of the discriminations against the commerce of the United States enumerated in subdivisions (a), (b), and (e) of this section are practiced by any country; and if and when such discriminatory acts are disclosed, it shall be the duty of the commission to bring the matter to the attention of the President, together with recommendations.

(h) Rules and regulations of Secretary of the Treasury
The Secretary of the Treasury with the approval of the President shall make such rules and regulations as are necessary for the execution of such proclamations as the President may issue in accordance with the provisions of this section.

(i) "Foreign country" defined
When used in this section the term "foreign country" means any empire, country, dominion, colony or protectorate, or any subdivision or subdivisions thereof (other than the United States and its possessions), within which separate tariff rates or separate regulations of commerce are enforced.