Section 201 of the Implementation Act authorizes the President to proclaim such modifications or continuation of any duty, such continuation of duty-free or excise treatment, or such additional duties, as the President determines to be necessary or appropriate to carry out or apply Articles 3.3, 3.5, 3.6, and 3.27, 3.28, and 3.29 and Annex 3.3 of the Agreement.