Except as provided in subsection (b), any significant goods, wares, articles, and merchandise mined, produced, or manufactured wholly or in part by the labor of North Korean nationals or citizens shall be deemed to be prohibited under section 1307 of title 19 and shall not be entitled to entry at any of the ports of the United States.

The prohibition described in subsection (a) shall not apply if the Commissioner of U.S. Customs and Border Protection finds, by clear and convincing evidence, that the goods, wares, articles, or merchandise described in such paragraph were not produced with convict labor, forced labor, or indentured labor under penal sanctions.