The United States has not done enough to change its meat labeling rules after losing a World Trade Organization challenge brought by Mexico and Canada, the WTO said on Monday.

The WTO ruled in June 2012 that the U.S. meat 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 than to U.S. meat.

The United States said it had met a deadline to change its rules, but Canada and Mexico said it had not done enough, a claim that was at least partially upheld by the ruling published on Monday.