Mexican President Vincente Fox is trying to convince Washington officials to stop "isolationist and discriminatory" restrictions that have blocked Mexican trucks from crossing into the United States, AP says.

Under the North American Free Trade Agreement (NAFTA), Mexican trucks were to travel throughout the United States by Jan. 1, 2000. U.S. officials later set a June 1, 2002 deadline, which was recently moved to mid-July.

Fox said if the United States does not comply with NAFTA, he would consider banning U.S. trucks from entering Mexico. He spoke to a group of Mexican transportation officials.

At issue is safety concerns about Mexican trucks, which U.S. officials say are not well-maintained and sometimes carry overweight loads or are driven by untrained drivers.