Passengers traveling to the United States will see more airport security screening and more armed air marshals on flights, Homeland Secretary Secretary Janet Napolitano said.“We must remain vigilant about the continued threat we face from Al-Qaeda,” Napolitano said. “We are taking an additional set of aviation security precautions to protect the American people.

“Some of these measures include enhanced random screening, additional federal air marshals on certain routes and adding individuals of concern to our terrorist watch list system.”

The announcement follows President Barack Obama’s wide-ranging security review, launched in the wake the attempted bombing of a trans-Atlantic jet on Christmas day.

Administration officials, who asked not to be named, said Thursday’s measures were part of wider vigilance in the face of continued Al-Qaeda threats originating from Yemen.

The Obama administration has faced fierce criticism for intelligence failures that allowed a young Nigerian man to board the Detroit-bound airliner, allegedly armed with explosives sewn into his underwear.

Umar Farouk Abdulmutallab (UFA), 23, has been charged with attempted murder and trying to use a weapon of mass destruction on board the Northwest flight carrying 290 people from Amsterdam.

The attack is thought to have been hatched in Yemen, bringing Al-Qaeda’s operations in that Arabian Gulf state into sharp focus.

“We do know AQAP (Al-Qaeda in the Arabian Peninsula) sent UFA our way and it would not be prudent to suddenly think that threats like this have passed with his failure,” an administration official told AFP.

“I am sure there will be more security measure announcements in the future as we constantly review all the information available to us.”

Earlier this week Canada put its airlines and airports on high alert after receiving “specific information” about new threats.

Meanwhile, Napolitano warned travelers visiting the United States that they should expected delays.

“Travelers should allot extra time when flying particularly into the United States from overseas,” she said.

While laborious airport screening irks many visitors to the United States, tougher measures are popular with Americans, according to recent polls.

On Thursday, a Quinnipiac University survey showed 63 percent of respondents said US anti-terror policies leaned too far toward protecting civil rights rather than national security.

Industry representatives said the tougher measures had been widely expected.

“We will have to come to grips with the reality that the air travel experience will be different,” said David Castelveter of the Air Transport Association, a trade association.

“It will not be the same tomorrow as it is today. We will have to turn up earlier and pack differently.”

But there are lingering concerns that security related delays will cost already struggling airlines.

To address those concerns Napolitano is scheduled to meet airline executives next week in Geneva, at the headquarters of the International Air Transport Association, an official for the organization said.

The meeting will come as airlines report their forth quarter earnings, which are expected to reflect the full price of delays related to the thwarted Christmas Day bomb plot.