Some Mexican trucks will be allowed to carry cargo anywhere in the United States as soon as a federal inspector general certifies safety and inspection plans, the Bush administration announced Friday.

The latest step toward implementing a controversial provision of the 1994 North American Free Trade Agreement drew instant condemnation from labor and driver-owner groups that fear the program will erode highway safety and eliminate U.S. jobs.

The decision was announced by a Transportation Department notice in the Federal Register, a dry, daily compendium of new federal rules read mostly by lobbyists and lawyers.

A one-year demonstration project allowing 100 Mexican motor carriers full access to U.S. roads will begin as soon as the department's inspector general certifies that safety and inspection plans and facilities are sufficient to ensure the Mexican trucks are at least as safe as U.S. trucks. That requirement was imposed by Congress.

Mexican trucks are now confined to commercial zones within about 25 miles of the border.

The inspector general's report to Congress is expected soon. The agency said it would complete any remedial actions he requested before beginning the program.

Teamster Union president Jim Hoffa questioned the timing — during Congress' August recess — of the administration's decision "to move forward with its hugely unpopular program to throw open our borders to unsafe Mexican trucks." Hoffa noted that the House voted last month to cut off funding for the program but that the Senate has yet to vote.

Todd Spencer, executive vice president of the Owner-Operator Independent Drivers Association, said the administration had only minimally complied with congressional directives but not with "the spirit of what Republicans and Democrats in Congress intended."

The Transportation Department acknowledged that most of the 2,300 public comments on the project challenged its safety and economic effects. But the agency concluded the demonstration, involving about 10 percent of the Mexican truckers who applied, "is sufficient to determine whether the safety oversight program" can ensure there will be no erosion of highway safety.