(CNN) -- President Obama warned Monday that the United States would respond aggressively to terrorism such as last week's botched attempt to blow up a U.S. airliner.
In his first public comment since the Christmas Day incident, Obama 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 defenses," Obama told reporters in a break from his Christmas holiday in Hawaii.
"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 U.S. homeland."
Earlier Monday, a statement attributed to al Qaeda in the Arabian Peninsula claimed responsibility for the attempted terrorist attack, saying it was in retaliation for alleged U.S. strikes on Yemeni soil.
Video: 'The threat's real'
In the incident aboard a Northwest Airlines flight making its final approach to the Detroit, Michigan, airport, a 23-year-old Nigerian allegedly attempted to detonate explosives hidden in his underwear, setting off a fire at his seat on the flight from Amsterdam, Netherlands.
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 U.S. air travelers 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.
"Apparently the suspect in the Christmas incident was in this system, but not on a watch list, such as the so-called no-fly list," Obama said. "So I have ordered a thorough review, not only of how information related to the subject was handled, but of the overall watch-list system and how it can be strengthened."
All screening policies, technologies and procedures for air travel will be reviewed "to determine just how the suspect was able to bring dangerous explosives aboard an aircraft and what additional steps we can take to thwart future attacks," Obama said.
"The American people should be assured that we are doing everything in our power to keep you and your family safe and secure during this busy holiday season," the president said.
