WASHINGTON- A top White House official said on Sunday the plot to bomb a Detroit-bound plane on Christmas Day exposed errors but he played down the need for a sweeping overhaul of the U.S. security system.

John Brennan, a senior White House adviser on counterterrorism, said there was no smoking gun that would have alerted authorities to the attempted bombing.

Facing criticism over the foiled attack on a Northwest Airlines flight, the Obama administration announced plans for closer screening of airline passengers from 14 countries.

They are Afghanistan, Algeria, Iraq, Lebanon, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia, Yemen, Cuba, Iran, Sudan and Syria. The last four are on the U.S. list of state sponsors of terrorism.

Passengers flying from or through those countries will be patted down and have their carry-on luggage searched, according to a U.S. official.

President Barack Obama, who returns on Monday from a vacation in Hawaii, has found himself on the defensive after a 23-year-old Nigerian man -- who U.S. authorities say was linked to al Qaeda -- was allegedly able to board the Christmas Day flight from Amsterdam with explosives in his underwear.

Security experts said there seemed to be a failure to connect the dots in the case of accused bomber Umar Farouk Abdulmutallab, whose father told the U.S. embassy in Nigeria of his concerns about his son's increased radicalization.

Brennan said on ABC's This Week that the incident pointed to the need to make the security and intelligence systems more robust and that Obama would do that.

But he added: There was no single piece of intelligence -- a smoking gun, if you will -- that said that Mr. Abdulmutallab was going to carry out this attack against that aircraft.

What we had, looking back at it now, were a number of streams of information, said Brennan, the deputy national security adviser for counterterrorism and homeland security.

Republicans have seized on the plane incident to accuse Obama, a Democrat, of not focusing enough on counterterrorism issues and said it exposed intelligence gaps that have lingered on since the September 11, 2001, hijacked-plane attacks.

Former Vice President Dick Cheney has led that charge, accusing Obama of pretending the United States was not at war.

Obama called for a review of what he termed human and systemic failures. He is to meet on Tuesday with intelligence advisers to discuss their review.

The attempted bombing has put a spotlight on Yemen, a poor Arab country where U.S. officials believe Abdulmutallab received training from a militant group.

The United States and Britain closed their embassies in Yemen on Sunday over concerns about possible militant attacks.

Brennan told Fox News Sunday that U.S. authorities believe Abdulmutallab was trained by al Qaeda in Yemen and was directed to carry out the plane attack by senior leadership of the militant group.


Brennan also disagreed with those who said the attempted bombing indicated a broader failure of the intelligence system such as occurred before the 2001 attacks blamed on al Qaeda. Turf wars between agencies and failure to share information were seen as a major problem then.

In the review so far, there's no indication whatsoever that any agency or department was not trying to share information, Brennan told Fox.

Homeland Security Secretary Janet Napolitano came under particularly intense criticism for initially saying the air security system worked. She later backpedaled and said the system had not worked in this case.

In comments that indicated that Napolitano's job was probably safe, Brennan praised her on ABC as a hard-working official of high caliber and experience.

The senior Republican on the Senate intelligence committee, Christopher Bond, said when the panel looks at the Christmas Day incident at a January hearing, it will be with an eye toward strengthening communication between the intelligence agencies.

The problem with the director of national intelligence, Denny (Dennis) Blair -- he has all of the responsibility and not enough authority, Bond said on CNN's State of the Union.

Thomas Kean, chairman of the 9/11 commission that studied the 2001 attacks, said the visit to the U.S. embassy by Abdulmutallab's father should have been enough to get the intelligence community to focus on him.

But Kean said he believed Obama would follow through and do the right things.

Republican Senator Jim DeMint of South Carolina criticized the administration on CNN, saying the decision to prosecute Abdulmutallab in the U.S. justice system rather than through military proceedings signaled it did not view the incident as an act of terror.

If we had treated this Christmas Day bomber as a terrorist, he would have been immediately interrogated military style rather than given rights of an American and lawyers, DeMint said. We probably lost valuable information.

(Additional reporting by Charles Abbott, Paul Simao, Adam Entous and James Vicini in Washington and Jeff Mason in Honolulu; Editing by Jackie Frank)