The US Government Accountability Office (GAO) has reported that the Transportation Security Administration (TSA) is falling short of its duty to ensure the safety of air cargo entering the United States.

"Ignoring a mandate from Congress and recommendations from the GAO on this critical security issue borders on the criminal," said the chairman of the House Committee on Homeland Security, Bennie Thompson, a Mississippi Democratic congressman.

The GAO report said the TSA had ignored Congress by failing to develop technology, to better identify, to track and to screen air cargo on all passenger and cargo aircraft. "TSA has yet to comply with this mandate. TSA has identified the primary threats but has failed to assess inbound air-cargo vulnerabilities," said the GAO.

Currently, TSA's screening system addresses domestic air cargo, leaving out air cargo entering the US, exempting some inbound cargo on passenger planes from inspection.

The GAO said it wanted the implementation of a systematic process to improve interagency communication to be used to strengthen the TSA's efforts in securing inbound cargo. "In addition, TSA must analyse air cargo security practices used by industry stakeholders and foreign governments to determine their applicability to the United States," the GAO said.

"This GAO report reiterates the need for the 100 per cent inspection of all cargo travelling on passenger planes," added committee member Christopher Shays, a Connecticut Republican congressman. "I think we owe it to all families who have lost loved ones in acts of terrorism to make our airlines as safe as we can."