Mexican truckers have asked the Mexican Congress and Economy Ministry to block access by U.S. trucks into Mexico under provisions of the North American Free Trade Agreement (NAFTA).

Trucking association Canacar says rules approved last year by the U.S. Congress to give Mexican trucks greater access to U.S. highways still discriminate against Mexican trucks and violate NAFTA.

The U.S. Department of Transportation is reviewing Mexican truck inspection plans, safety monitoring programs and border state law enforcement. Meanwhile, a federal court last week ruled against U.S.-based labor, trucking and environmental groups who sought to bar Mexican truck entry into the United States.