19 U.S. Code § 3355 - Termination of relief authority
(a) General rule
Except as provided in subsection (b) of this section, no import relief may be provided under this subpart—
(2) in the case of a Mexican article, after the date that is 10 years after the date on which the Agreement enters into force;
unless the article against which the action is taken is an item for which the transition period for tariff elimination set out in the United States Schedule to Annex 302.2 of the Agreement is greater than 10 years, in which case the period during which relief may be granted shall be the period of staged tariff elimination for that article.
Import relief may be provided under this subpart in the case of a Canadian article or Mexican article after the date on which such relief would, but for this subsection, terminate under subsection (a) of this section, but only if the Government of Canada or Mexico, as the case may be, consents to such provision.