19 U.S.C. § 4561: Temporary entry

Upon a basis of reciprocity secured by the USMCA, an alien who is a citizen of Canada or Mexico, and the spouse and children of any such alien if accompanying or following to join such alien, may, if otherwise eligible for a visa and if otherwise admissible into the United States under the Immigration and Nationality Act (8 U.S.C. 1101 et seq.), be considered to be classifiable as a nonimmigrant under section 101(a)(15)(E) of such Act (8 U.S.C. 1101(a)(15)(E)) if entering solely for a purpose specified in Section B of Annex 16–A of the USMCA, but only if any such purpose shall have been specified in such Annex on the date of entry into force of the USMCA. For purposes of this section, the term “citizen of Mexico” means “citizen” as defined in article 16.1 of the USMCA.