The Section 232 was effective on March 23rd ( US local time) that meant the US government would impose a high tariff for imported steel and aluminum. At the meantime, the White House also announced the exemption list. The countries included NAFTA, Canada, Mexico, South Korea, EU countries, Australia, Argentina, Brazil. However, Taiwan and Japan were not in the list.

Donald Trump signed the order of Section 232 on March 8th for imported steel and aluminum, and Canada and Mexico were excluded temporarily.

Other country could be on the exemption list if they could ensure the product would not threaten to the US nation security.