"The partnership will work best if it is comprehensive," says Customs commissioner Robert C. Bonner. "This marks the next level of a program that will simultaneously protect national security and promote the more expeditious processing of commerce."

Customs says importing services will establish policies and practices to enhance security for themselves and their clients.

C-TPAT was launched with importers in April and the program soon rolled over to encompass carriers. The program encourages companies to progressively build more secure supply chains, with the reward of expedited security clearance once cargo arrives at U.S. ports and borders.

C-TPAT eventually will extend to all international supply chain participants. In the future Customs says it will extend C-TPAT membership to ports, warehouse and terminal operators and manufacturers.