U.S. will keep pressure on extremists: Obama

President Barack Obama says the U.S. will use every element of national power to defeat violent extremists, plotting terror attacks against his country. In his first public remarks since the attack on the US airliner, Obama says it's critical to learn from the incident and take necessary measures.

President Barack Obama said, "The first review involves our watch list system, which our government has had in place for many years to identify known and suspected terrorists so that we can prevent their entry into the United States. 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'. 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. The second review will examine all screening policies, technologies and procedures related to air travel. We need 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 on Monday vowed to track down those behind an attempt  to bring down a U.S. passenger airline on Christmas Day as  he announced stepped-up measures to ensure U.S. flight  safety. REUTERS/Yuri Gripas/Files