A Senate panel will take a close look at a new program to allow approved Mexican trucks make deliveries beyond Southwest border zones after some groups' concerns about potential safety and security risks.

The Bush administration program expands the area for the first time since 1982. Congress authorized the program in 2001 requiring safety regulations before the program could begin.

Transportation officials say the program aims to streamline the process that requires Mexican truckers to stop and wait for U.S. trucks to take their cargo and transfer it. The program also allows U.S. trucks to make deliveries into Mexico.

Current requirements prevent trucks from moving past a 20 to 25-mile area inside the U.S. border. Critics of the new program say these limits protect national security.

A Senate panel is expected to review the program on March 8 after Sen. Patty Murray, D-Wash., announced the hearing last week.

Public Citizen, a watchdog group, joined highway safety organizations calling on lawmakers to review the program.

“The Federal Motor Carrier Safety Administration (FMCSA) admits that many states have not authorized law enforcement to stop trucks without legal registration and operating authority from hauling their cargo,” Joan Claybrook, president of Public Citizen, said in a statement. “Yet FMCSA has documented that one in five short-haul trucks currently crossing the border is being placed out of service because of equipment defects.”

The one-year pilot program will allow about a hundred Mexican trucking companies to bring goods across the border. Current requirements allow trucks to unload their cargo at warehouses before transfer to a U.S. truck.

The International Brotherhood of Teamsters support keeping the border closed.

"They are playing a game of Russian Roulette on America's highways," Teamsters President Jim Hoffa said in a statement. "Mexico refuses to meet their end of the bargain yet President Bush rewards them with open access to American highways. It is the American driving public who will pay the consequences."

Hoffa called on Congress to hold hearings and review the program.

“We are committed to retaining a high level of security and safety standards under this program,” Homeland Security Secretary Michael Chertoff said in response to those concerns. “The tough security measures we already have in place will remain unchanged, resulting in a smart and secure approach to safeguarding the border, while allowing for American and Mexican carriers to deliver cargo outside of arbitrary commercial zones.”

The process of unloading Mexican cargo at U.S. warehouses along the border "is a waste of time, energy and money, and that is about to change," said Mary Peters, U.S. Department of Transportation secretary. "Now that the safety and security programs are in place, the time has come for us to move forward on a long-standing promise with Mexico."

The trucks will still be subject to inspection by U.S. Customs and Border Protection officers, said Michael P. Jackson, deputy secretary of the Department of Homeland Security.

The Associated Press contributed to this report.