Air travelers won't have to take their shoes off during security screenings in the future, said U.S. Homeland Security Secretary Janet Napolitano.

"One of the first things you will see over time is the ability to keep your shoes on," Napolitano said today at a forum hosted by Politico Playbook in Washington. She didn't specify when the change would take place.

Napolitano said restrictions on the amount of liquids passengers can bring on a plane will likely remain in place for the foreseeable future because technology hasn't yet progressed to differentiate between explosives and harmless liquids.

Airline customers have complained since the Sep. 11 attacks about elements of tighter airport security. Representative Mike Rogers, an Alabama Republican who heads the House subcommittee overseeing the Transportation Security Administration, has urged the agency to only require passengers suspected of posing a threat to remove shoes and belts.

General Electric Co. (GE) and other companies have sought for years to get U.S. government approval for their shoe-scanning devices. In 2009, Fairfield, Connecticut-based GE said it would sell an 81 percent stake in its homeland-protection business to Safran SA for US$580 million.

Deadline Ahead

TSA's goal was to have shoe scanners deployed at airports by 2015, according to an October 2009 report by the Government Accountability Office, which audits programs for Congress.

The agency has tested machines made by L3 Communications Holdings Inc., in which passengers step on a black mat to have their shoes scanned.

No decision has been made on the technology.

TSA has said it will begin later this year "Known Traveler," a pilot program to allow frequent travelers who provide additional personal information to keep their shoes on and laptops in bags.

The U.S. required passengers to remove their footwear and send them through scanners with carry-on luggage after Richard Reid in 2001 attempted to set off explosives concealed in his shoe while on a flight over the Atlantic Ocean.

Napolitano said while her department is remaining vigilant before the 10th anniversary of the Sep. 11 terrorist attacks, there are no credible, "pending" threats to the U.S.

Still, she said, documents collected in the Pakistani compound where former al-Qaeda chief Osama bin Laden was killed revealed he considered the anniversary an "iconic" date.

While terrorists are focused on aviation, particularly targeting U.S. and European planes, a "spectacular" attack in the mold of Sep. 11 is unlikely, she said.

Homegrown terrorism is a "key concern," particularly the threat of an attack by a "lone wolf" terrorist inspired by al- Qaeda to act, she said.