A World Trade Organization (WTO) dispute settlement body announced Tuesday that the  United States must bring its country-of-origin labeling (COOL) rules into compliance with rules outlined in an earlier WTO decision by May 23, 2013.

The ruling described the WTO order saying, "this period of time should allow the United States to implement the recommendations and rulings of the dispute settlement body regardless of whether it decides to do so by regulatory action alone or by legislative action followed by regulatory action."

The WTO ruled on June 29 that the U.S. country-of-origin labeling program, known as COOL, unfairly discriminated against Canada and Mexico because it gave less favorable treatment to beef and pork imported from those countries, which brought the case, than to U.S. meat.

That decision gave the United States an unspecified amount of time to comply.

The labeling program has led to a sharp reduction in U.S. imports of Canadian pigs and cattle, because it forced U.S. packers to segregate those animals from U.S. livestock at greater cost. Some U.S. groups, however, have said COOL offers consumers valuable information about the origin of their food.

"We expect that the U.S. will bring itself into compliance with its WTO obligations by May 2013 as determined by the arbitrator for the benefit of producers on both sides of the border," Canadian International Trade Minister Ed Fast and Agriculture Minister Gerry Ritz said in a joint statement.

Canada and Mexico had asked for compliance by late January and March of 2013 respectively.

The U.S. labeling law requires grocers to put labels on cuts of beef, pork, lamb, chicken and ground meat or post signs that list the origin of the meat.

U.S. officials have said the WTO's June ruling allowed the United States to continue to require country-of-origin labels, but Washington will have to alter the program to ensure it does not create an impermissible trade barrier.

"The United States remains committed to ensuring that consumers are provided with information about the origin of the beef and pork products they buy at the retail level," Nkenge Harmon, a spokesperson for U.S. Trade Representative Ron Kirk, said on Tuesday. "We intend to bring the COOL requirements into compliance within the period of time established by the arbitrator, and we will continue to work with USDA, Congress, and interested stakeholders in order to do so."