Mexico and Canada have led opposition to COOL along with the US beef industry. Groups representing US, Canadian and Mexican meat-industry interests have fought COOL in the courts, while trade officials turned to the WTO. Canada and Mexico have threatened to impose retaliatory tariffs on American goods if the US refuses to withdraw COOL.
COOL requires meat packers to label muscle cuts of meat with information about where each production step occurred. The US already has lost an appeal of a WTO challenge brought by Canada and Mexico in 2012.