Transportation Secretary Mary Peters is urging Congress to continue allowing Mexican trucks full access to roads in the United States.

She warned on Monday halting the trucks would hurt the agricultural economy and other businesses.

The Bush administration began allowing Mexican trucks full access to U.S. roadways last year to comply with the North American Free Trade Agreement. The agreement also allows U.S. trucks into Mexico.

Mexican trucks previously had to stop within a buffer border zone and transfer their loads to U.S. trucks.

Congress tried to stop the program by stripping money for the project from the Department of Transportation last year.

Some groups oppose trucks' entry fearing their drivers may compete with U.S. drivers or their trucks are unsafe.