US security agencies had enough intelligence to disrupt a plot to blow up a plane last month, but failed to act, President Barack Obama has said.

美国总统奥巴马称，对于上月的密谋爆炸飞机事件，美国安全机构完全有能力使其瓦解，但却未能做到。

The intelligence community had failed to "connect the dots", Mr Obama said, adding: "That's not acceptable, and I will not tolerate默许，宽恕 it."

Enhanced airport screening and a review of the US watch-list system were ordered after the 25 December attempt.

A Nigerian man known to US officials has been charged over the alleged¹ plot阴谋，情节.

Umar Farouk Abdulmutallab later gave "actionable" intelligence to US officials, the White House said.

Mr Abdulmutallab's name was in a US database of about 550,000 suspected terrorists, but was not on a list that would have subjected him to additional security screening审查，筛选 or kept him from boarding the flight.

'Red flags'

Mr Abdulmutallab, 23, was allegedly trained in Yemen - a country that has come under increased scrutiny²监视 from the US since his arrest.

The US suspended the repatriation遣送回国 of Yemeni prisoners from its Guantanamo Bay detention⁴ centre in the wake of紧紧跟随 the plot, but Mr Obama reiterated重申 that he would push on with his plan eventually to close the centre.

Mr Obama spoke⁶ on Tuesday after being briefed on security reviews ordered after Mr Abdulmutallab's arrest.

Secretary of State Hillary Clinton, Defence Secretary Robert Gates, Homeland Security Secretary Janet Napolitano, CIA Director Leon Panetta and FBI Director Robert Mueller were among those who attended the security meeting in Washington.

In his remarks, Mr Obama said the US intelligence community had known of "red flags" indicating plans by al-Qaeda in the Arabian Peninsula to strike US targets in Yemen and the US.

He said officials now knew that al-Qaeda had been working with Mr Abdulmutallab.

"But our intelligence community failed to connect those dots, which would have placed the suspect on the no-fly list.

"In other words, this was not a failure to collect intelligence, it was a failure to integrate联系，整合 and understand the intelligence that we already had."

He had stern严厉的，坚定的 words for the trained professionals and analysts⁷ who had access to the information.

"I will accept that intelligence by its nature is imperfect, but it is increasingly clear that intelligence was not fully⁸ analysed or fully leveraged," he said.

White House spokesman Robert Gibbs told the media on Tuesday that Mr Abdulmutallab had "spent a number of hours with FBI investigators⁹ in which we gleaned收集 usable, actionable intelligence".