Washington, Jan 8 - As a White House review found chinks galore in US intelligence armour leading up to the botched Dec 25 terror bombing of a US-bound jetliner, President Barack Obama issued a stern warning to government agencies to shape up fast.

"I will hold my staff, our agencies and the people in them accountable when they fail to perform their responsibilities at the highest levels," Obama said at the White House Thursday outlining a series of major reforms. But "ultimately, the buck stops with me."

America's first line of defence against terrorism is "timely, accurate" intelligence that is properly integrated, Obama said. "That's not what happened" before the attack, he noted.

According to authorities, 23-year-old Nigerian national Umar Farouk AbdulMutallab tried to detonate explosives hidden in his underwear as a Northwest Airlines flight from Amsterdam made its final approach to Detroit on Dec 25. The device failed to fully detonate, instead setting off a fire at AbdulMutallab's seat.

Obama cited three problems that contributed to the government's failure to prevent the attack.

First, the intelligence community knew that an al Qaeda affiliate in Yemen intended to strike the United States and was recruiting operatives for the task, the president said. But intelligence operatives "did not aggressively follow up on and prioritize particular streams of intelligence related to a possible attack against the homeland," he noted.

Second, there was a "larger failure of analysis, a failure to connect the dots of intelligence that existed across our intelligence community."

Third, the intelligence failure contributed to flaws in the country's watch-listing system that resulted in the alleged bomber not being added to the no-fly list.

"Rather than a failure to collect or share intelligence, this was a failure to connect and understand the intelligence that we already had," Obama said. The president said he had ordered four key reforms.

First, he ordered the intelligence community to assign specific responsibility to individuals to pursue all leads on specific high-priority threats.

"We must follow the leads that we get, and we must pursue them until plots are disrupted. And that means assigning clear lines of responsibility," he said.

Second, intelligence reports will be distributed more widely and quickly, he added.

Third, Director of National Intelligence Dennis Blair will overhaul current intelligence analysis efforts.

Fourth, the government will strengthen the criteria used to add people to its terrorist watch lists, particularly the no-fly list.

"Taken together, these reforms will improve the intelligence community's ability to collect, share, integrate, analyze and act on intelligence swiftly and effectively," Obama said.

Obama noted, however, that most airports in the world and in the United States do not have the technology necessary to detect the explosives used in the botched attack.

"There's no silver bullet to securing the thousands of flights into America each day, domestic and international," he warned.

Obama said he was directing the Homeland Security Department to improve international partnerships to improve aviation security and boost screening at airports around the world. Obama also said he was establishing accountability reviews for national security and intelligence agencies. His national security adviser, John Brennan, will report to him every 30 days on the reviews, he said. (IANS)