Canada and Mexico will begin imposing more than $1 billion in tariffs on U.S. products as soon as this week in retaliation for the U.S. country-of-origin labeling (COOL) law for meat, stepping up pressure on Congress to immediately repeal the controversial measure.

The retaliation is expected to include a 100 percent tariff on U.S. beef, as well as higher tariffs on pork, corn, soybeans and other products.

"The COOL rule has been a failure on all accounts. It has cost our livestock industry billions in implementation, it has...