Obama vows to go aggressively after US plane attackers

President Barack Obama vowed to respond aggressively to terrorism as an Al Qaeda faction claimed responsibility for last week's foiled attempt by a Nigerian to blow up a US airliner.

Taking a break from his Christmas holiday in Hawaii, Obama in his first public comment since the Christmas Day incident on the Amsterdam-Detroit flight, said he directed his national security team to "keep up the pressure on those who would attack our country."

"We do not yet have all the answers about this latest attempt, but those who would slaughter innocent men, women and children must know that the United States will do more than simply strengthen our defences," he told reporters Monday.

"We will continue to use every element of our national power to disrupt, to dismantle and defeat the violent extremists who threaten us, whether they are from Afghanistan or Pakistan, Yemen or Somalia, or anywhere where they are plotting attacks against the US homeland."

Obama's comments came as a statement attributed to Al Qaeda in the Arabian Peninsula claimed responsibility for the attempted terrorist attack, saying it was in retaliation for alleged US strikes on Yemeni soil.

In the statement, published on radical Islamist Web sites, the group hailed the "brother" who carried out the "heroic attack." The group as cited by CNN said it tested a "new kind of explosives" in the attack, and hailed the fact that the explosives "passed through security."

"There was a technical problem that resulted in a non-complete explosion," the message said. The group threatened further attacks, saying, "since Americans support their leaders they should expect more from us."

"We have prepared men who love to die," the statement dated Saturday said.

Obama said courageous actions by other passengers and crew members helped avert a disaster, and he outlined steps including reviews of passenger screening procedures and terrorism watch lists for air travel as a response.

"This was a serious reminder of the dangers that we face and the nature of those who threaten our homeland," Obama said.

"Had the suspect succeeded in bringing down that plane, it could have killed nearly 300 passengers and crew - innocent civilians preparing to celebrate the holidays with their families and friends."

In an effort to reassure jittery US air travellers at the height of the holiday season, Obama said screening and security procedures for all flights were immediately enhanced, including an increase in the number of air marshals on international flights.

The federal system for tracking potential terrorism suspects will be reviewed because the latest incident showed it had possible failings, the president said.

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