Public Citizen and the Environmental Law Foundation, joined by the International Brotherhood of Teamsters, the California Federation of Labor AFL-CIO and the California Trucking Assn., asked the court last week to limit trucks from Mexico to a 20-mile zone along the border until the United States reviewed the impact they might have on air quality.
The government told the court that it was at least 30 days away from issuing permits to the Mexican trucks.
NAFTA included a clause that allowed Mexican trucks beyond that zone in 1999. Former President Bill Clinton imposed a moratorium that year after the Teamsters and other groups questioned the vehicles' safety.
Last month, President George W. Bush signed off to allow trucks outside the zone and requiring them to meet all United States safety standards.