“This was not a failure to collect intelligence, it was a failure to integrate and understand the intelligence that we already had,” Mr. Obama said after a two-hour meeting with his national security team at the White House. He added, “We have to do better, we will do better and we have to do it quickly. American lives are on the line.”

The president renewed his commitment to close the military prison at Guantanamo Bay, Cuba, but said the transfers of detainees to Yemen would be suspended immediately. He said the intelligence and law-enforcement reviews of the terror plot would be completed this week and additional security measures would be announced in the coming days.

“Every member of my team understands the urgency of getting this right,” Mr. Obama said in brief statement delivered from the Grand Foyer of the White House. His remarks suggested that he was standing by his top national security officials, including those whose agencies failed to communicate with one another.

Mr. Obama convened the meeting of his national security team in the Situation Room of the White House, bringing together nearly two dozen advisers for their first face-to-face session since an attempted bombing on a Christmas Day flight drew fresh attention to deficiencies in airline security.

The president called the threat against the United States “a challenge of the utmost urgency.”

The president made the remarks after meeting with his national security team in the Situation Room of the White House.

Mr. Obama ordered a review of security procedures and received a preliminary report on Dec. 31.

The meeting came after the Transportation Security Administration instructed airlines on Monday to begin conducting full-body searches for passengers bound for the United States from Yemen, Nigeria, Afghanistan, Saudi Arabia and 10 other countries.

The White House’s decision to mandate extra scrutiny for people flying into the United States from the 14 mostly Muslim countries provoked criticism from foreign officials and skepticism from some security experts that the measures would be effective.