The announcement came just hours before Barack Obama, the US president, was expected to unveil additional security measures for air travel following the suspected bombing attempt.

Watchlist system

Administration officials said the proposed overhaul - aimed at thwarting any possible future attacks - includes changes to the much-criticised airline watchlist system.

Bob Ayers, a former US intelligence officer and current security consultant said Obama's announcement is an attempt to "correct the perception that he's being soft on national security".

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"It provides him with an opportunity to demonstrate that he's concerned and he's tough and he's going to do something about this problem," Ayers told Al Jazeera.

Ayers also warned against blaming the incident solely on the failure of the US intelligence process.

"The man still had to go through a security checkpoint. He was allowed onto an aircraft at his point of debarkaction without even having a passport.

"That's not an intelligence failure, that's an airport security failure."

Abdulmutallab was allowed to board a plane in both Lagos and Amsterdam despite US intelligence agencies and the state department having received information that many critics have said should have seen him placed on a so-called "No-Fly" list.

In the wake of the 9/11 attacks in New York and Washington, the FBI and other US agencies drew up lists intended to prevent suspected criminals or people labelled terrorists from boarding flights to and within the US.

The "Watch List" comprises 550,000 names of people who US authorities believe have possible ties to terrorism but do not present a specific threat and are allowed to fly.

The much smaller "No-Fly" list comprises about 4,000 people who the US claims present a known, specific or suspected threat to aviation.

'Enhanced screening'

Hillary Clinton, the secretary of state, Robert Gates, the defence secretary, Leon Panetta, head of the CIA, Robert Mueller, director of the FBI, and Janet Napolitano, homeland security secretary, were among several administration officials meeting Obama to discuss the new measures.

US authorities have already imposed stricter screening regulations for US-bound airline passengers from Yemen, Nigeria and 12 other countries, including possible full-body pat-downs, searches of carry-on bags, and full-body scanning.

But the "enhanced screening" rules got off to a patchy start, amid complaints of delays and discrimination.

Several European governments, including Germany, France and Spain, said they were still studying the rules before implementing them.

With 13 of the 14 nations cited by the US Transportation Security Administration (TSA) being majority Muslim states, the Council on American-Islamic Relations (CAIR), a Muslim civil rights and advocacy organisation, said the procedures amounted to ethnic profiling.

"Under these new guidelines, almost every American Muslim who travels to see family or friends or goes on pilgrimage to Mecca will automatically be singled out for special security checks - that's profiling," Nihad Awad, CAIR's national executive director, said in a statement.

Amsterdam investigation

Meanwhile, in the Netherlands, Dutch investigators said they found no evidence to suggest Abdulmutallab had contacted accomplices at an airport in Amsterdam.

Officials said he underwent a security interview and check and did nothing unusual in his three-hour stopover.

"Investigations so far have uncovered no indication that the suspect contacted possible accomplices at Schiphol, left the transfer area or behaved suspiciously," the national prosecutor's office said in a statement.

"At the moment, it appears that he was already in possession of the explosives before he reached Schiphol."