Mexico's Agriculture Ministry said it will fight the United States new "dolphin-safe" tuna labeling rules at the World Trade Organization, arguing they are unfair to Mexican fishermen. "Mexico will take its case to the WTO, arguing that the United States has not met its international obligations," the ministry said in a statement. "If the violation is confirmed, Mexico could impose trade reprisals against the United States." The decades-old spat appeared to turn a corner in May last year when the WTO backed Mexico in its dispute with its northern neighbor, saying the U.S. requirement that tuna be labeled "dolphin-safe" disadvantaged Mexico's fishing industry. The WTO, which has no enforcement power, gave Washington 13 months to comply with its ruling, due to expire on July 13. On Tuesday, the United States published its updated guidelines on tuna labeling, but Mexico's government argued this fell short of what the WTO had demanded. The dispute centers on the technique of using dolphins to round up tuna, which the United States says disqualifies some Mexican tuna from being labeled dolphin-safe. Mexico says the methods its companies use to harvest tuna do not harm dolphins and the way the United States defines dolphin-safe tuna unfairly restricts trade. Mexico's tuna industry employs more than 10,000 people and generated $112 million in 2011. (Reuters)