TSA is developing a faster airport security screening process for passengers considered to be low security risks, said a Reuters report.

"It is something we are working on in a number of ways," TSA Administrator John Pistole told a meeting of airport executives during a speech in Atlanta.

The new "expedited" procedures could include a separate line for passengers deemed low-risk travellers, the report said.

He did not, however, say when any changes would be implemented and called for input from airport executives on ways to develop more efficient security checkpoints.

In March, a leading travel industry group, the U.S. Travel Association, said the U.S. government should adopt a trusted traveller program and order airlines to permit passengers to check one bag for free to make airport screening faster and encourage more travel.

"I will be the first to admit that our system is not without shortcomings," Pistole said, referring to the more intrusive screening procedures. "Clearly, the system is not without flaws."

Identifying low-risk travellers would allow authorities to focus resources on conducting more extensive screening of high-risk passengers, such as the use of human intelligence to identify dangerous passengers before they arrive at airports, the report said.

Pistole defended the screening process as being effective in preventing more attacks. But he cautioned that threats remain, particularly after the U.S. raid on May 2 in Pakistan that killed al Qaeda leader Osama bin Laden.