Mexican trucks will begin shipping long-haul freight far into U.S. territory at the end of August or in early September after a bilateral agreement was signed earlier this month, the Mexican government said.

"We hope that by the end of August or early September the first company can enter with full rights," Economy Secretary Bruno Ferrari told reporters in Washington after a three-day visit that ended Thursday and included meetings with U.S. Trade Representative Ron Kirk.

That first company, based in Monterrey, will be joined later by another 20 that had requested the right to transport cargo on U.S. roads before Washington barred access to Mexican trucks in 1995, Ferrari said, adding that those other firms could begin shipping freight deep inside the United States "before year's end,"

Mexico expects other companies that are now submitting their paperwork for the program to be able to enter the United States within 18 months after the application date, as stipulated in the bilateral accord signed on July 6.

Until now, despite the provisions of the 1994 North American Free Trade Agreement, Mexican trucks had been restricted to a narrow stretch along the border.

A pilot program was established in 2007 to allow Mexican trucks greater access and when it was cancelled two years ago the Mexican government responded by slapping punitive tariffs on $2.3 billion of U.S. products.

Those tariffs were partly suspended after this month's agreement and are to be removed completely once the first Mexican truckers are allowed into the U.S. interior.

Ferrari said he was optimistic about the Cross Border Freight Truck Program deal and hailed the fact that the applications that Mexican trucking firms submitted two decades ago for access to U.S. roads remain valid.

"In the talks we stressed that we didn't want a new program, but just to give effect to the previous one, which was not interrupted for reasons in Mexico but rather due to problems in this country (the United States)," the secretary said.

"I think there'll be a lot of interest from Mexican companies," the secretary said, noting that trucks transport roughly $275 billion worth of annual cargo shipments between the two countries, or 70 percent of the total.

Mexico's Communications and Transportation Secretariat estimates that the new agreement will expedite the 4.5 million annual truck crossings, generating some $675 million in cost savings.