US President Barack Obama laid blame Saturday on an al-Qaida affiliate for a Christmas Day terrorist attack that has prompted a top-to-bottom review of how the nation's intelligence agencies failed to prevent the botched bombing aboard a Detroit-bound airliner.In his most direct public language to date, the president described the path through Yemen of 23-year-old Umar Farouk Abdulmutallab, the Nigerian accused of trying to destroy Northwest Flight 253. The president also emphasized that the United States would continue its partnerships with friendly countries - citing Yemen, in particular - to fight terrorists and extremist groups around the globe.Obama's homeland security team has been piecing together just how Abdulmutallab was able to board the plane. Officials have described flaws in the system and by those executing the strategy and have delivered a preliminary assessment.A senior administration official had said the United States was increasingly confident there was a link between Abdulmutallab and an al-Qaida affiliate, but Obama's statement is the strongest connection between the two."We're learning more about the suspect," Obama said in his weekly radio and Internet address that the White House released on Saturday as the president vacationed in Hawaii."We know that he traveled to Yemen, a country grappling with crushing poverty and deadly insurgencies. It appears that he joined an affiliate of al-Qaida, and that this group - al-Qaida in the Arabian Peninsula - trained him, equipped him with those explosives and directed him to attack that plane headed for America," the president said.Officials have said Abdulmutallab's father warned the US Embassy in Nigeria that his son had drifted into extremism in the Al Qaida hotbed of Yemen. Abdulmutallab's threat was only partially digested by the US security apparatus and not linked with a visa history showing the young man could fly to the United States.Obama has ordered a thorough look at the shortcomings that permitted the plot, which failed not because of US actions but because the would-be attacker was unable to ignite an explosive device.Intelligence officials prepared for what was shaping up to be uncomfortable hearings before Congress about miscommunication among anti-terror agencies and sweeping changes expected under Obama's watch. The president has been vocal in his criticism of the agencies and against extremists who would harm the United States."This is not the first time this group has targeted us," Obama said. "In recent years, they have bombed Yemeni government facilities and Western hotels, restaurants and embassies, including our embassy in 2008, killing one American.""So, as president, I've made it a priority to strengthen our partnership with the Yemeni government - training and equipping their security forces, sharing intelligence and working with them to strike al-Qaida terrorists," he said.The United States provided Yemen $67 million in training and support under the Pentagon's counterterrorism program last year. Only Pakistan got more, with some $112 million.Obama said the money had been well spent: "Training camps have been struck, leaders eliminated, plots disrupted. And all those involved in the attempted act of terrorism on Christmas must know - you too will be held to account."At the same time, administration officials warned this week that Obama also would hold accountable his own government. To that end, Obama has summoned homeland security officials from across the government to meet with him in the White House Situation Room on Tuesday.Obama was expected to run the meeting and press his team on how they missed what appear to be clear connections.