Washington - President Barack Obama said Tuesday that U.S. intelligence agencies could have prevented the attempt to bomb an airliner on Christmas Day, and used a grim and forceful White House statement to demand rapid improvements in efforts to protect Americans from attack.

"This was not a failure to collect intelligence," Obama said after meeting with senior national security and intelligence officials, "it was a failure to integrate and understand the intelligence that we already had. ....That's not acceptable, and I will not tolerate it."

The administration has been criticized by Republicans and some Democrats for intelligence lapses that allowed Nigerian Umar Farouk Abdulmutallab, allegedly carrying undetected explosives, to board the Amsterdam-Detroit flight despite reports that he had met with al-Qaida-affiliated extremists in Yemen known to be planning to attack the United States.

"Our intelligence community failed to connect those dots," the president said. "We have to do better, and we will do better, and we have to do it quickly. American lives are on the line."

On Obama's first full day back at the White House after an 11-day vacation in Hawaii, his words were far sharper than his previous comments since the incident, conveying a controlled anger about what he had heard in preliminary reviews of what went wrong.

A White House official quoted Obama using even more blunt language in the Situation Room meeting. "This was a screw-up that could have been disastrous. We dodged a bullet, but just barely," he reportedly said. Although Abdulmutallab allegedly tried to detonate the explosive as the plane started its descent into Detroit with nearly 300 people aboard, it did not ignite because of "technical difficulties," according to a statement by al-Qaida in the Arabian Peninsula claiming responsibility for the plot.

In his public statement, at a lectern set up in the Grand Foyer of the White House, Obama listed steps that have been taken, including expansion of the U.S. "no-fly" list to include people with Abdulmutallab's profile, enhanced screening for anyone flying to the United States from an expanded list of "countries of interest," additional screening and security on all domestic or U.S.-bound international flights, and an automatic check of terrorism suspects to determine whether they possess valid U.S. visas.

"In the days ahead," Obama said, "I will announce further steps to disrupt attacks, including better integration of information and enhanced passenger screening for air travel." A summary of the ongoing review of the terrorist watch-listing system that did not identify Abdulmutallab, he said, will be made public "within the next few days."

The changes, including the addition of hundreds of people to airline watch lists, have prompted accusations by civil liberties groups that the administration is profiling passengers on the basis of national origin and religion.

Addressing Republican demands that he revisit his plans to close the U.S. military prison at Guantanamo Bay, Cuba, Obama also said he has suspended the repatriation of least 30 Yemenis already cleared for release by a Justice Department-led interagency review. Nearly half of about 200 detainees remaining at the prison are from Yemen.

But he said he will continue with already delayed plans to close the facility, which he said "has damaged our national security interests and become a tremendous recruiting tool for al-Qaida."

"In fact," he added, "that was an explicit rationale for the formation of al-Qaida in the Arabian Peninsula."

The Yemen-based group, known as AQAP, was founded in part by prisoners released from Guantanamo Bay during George W. Bush's administration. Yemen's weak government, poverty and inhospitable terrain have provided fertile ground for the growth of the organization, which Yemeni military forces targeted last month in two U.S.-assisted airstrikes.

The administration has cited extensive intelligence indicating that AQAP is still planning an attack on the United States. The U.S. Embassy in Yemen was closed Sunday for security reasons but was reopened Tuesday, officials said, along with those of Britain and France. Yemeni security officials said thousands of their forces had hemmed in al-Qaida militants in three provinces and staged a raid outside the capital in which two al-Qaida fighters were killed, Reuters reported from Sanaa, the capital.

A statement by the U.S. Embassy there said that the operations "addressed a specific area of concern and have contributed to the embassy's decision to resume operations."

Abdulmutallab, 23, is due in federal court in Michigan for a bail hearing Friday, and authorities have expressed hope that he will agree to a plea deal in exchange for a reduced prison term. His public defender, Miriam Siefer, did not return calls or e-mail messages seeking comment Tuesday.

Federal sources, speaking on the condition of anonymity so as not to interfere with the case, said Abdulmutallab provided useful information to the FBI in interviews on Dec. 25, the day of his arrest, explaining his travels in Yemen and connections to the al-Qaida group there. Investigators are pursuing leads overseas in response to that information, sources said, and the United States and Yemen were considering responses, including additional military attacks targeting AQAP's operational leaders and radical Yemeni American cleric Anwar al-Aulaqi, who survived a bombing attack last month.

FBI investigators hope to compare the remnants of a similar explosive device used in an August attempt to kill a senior Saudi government official to determine whether it employed the same technology and possibly was constructed by the same bomb-maker.

Intelligence officials have said that Abdulmutallab first came to U.S. attention as a possible terrorism suspect in November, when his father approached the U.S. Embassy in Nigeria to say that his son was in Yemen, had cut off contact with his family and was in bad company. A cable sent to Washington by diplomatic and CIA officials at the embassy said they had been given information that the "subject may be involved with Yemeni-based extremists."

Under its existing guidelines, the National Counterterrorism Center in suburban McLean, Va., did not consider the information alarming enough to forward Abdulmutallab's name to the FBI's Terrorist Screening Center, which manages terrorism watch lists throughout the government. Because no check was done, it was not known that he possessed a valid U.S. multiple-entry visa.

Other information in intelligence databases that could have flagged the report for more scrutiny included National Security Agency intercepts - beginning in August, when Abdulmutallab arrived in Yemen - that mentioned "Umar Farouk" and "the Nigerian," as well as an anti-U.S. attack being planned for the holidays. There were also reports indicating that the Nigerian had been in direct contact with al-Aulaqi.

- Staff writers Peter Finn, Carrie Johnson, Ellen Nakashima and Scott Wilson contributed to this report.