A “SYSTEMIC failure” by American intelligence allowed the alleged terrorist behind the Christmas Day airliner bomb plot to board the aircraft despite warnings about his extremist views, US President Barack Obama said last night.

Mr Obama said initial investigations into the failed attack had found the information passed on by the father of Umar Farouk Abdulmutallab was not properly shared, meaning he was not barred from flying.

“Where our government has information on a known extremist and that information is not shared and acted upon as it should have, so that this extremist boarded a plane with dangerous explosives that could have cost nearly 300 lives, a systemic failure has occurred and I consider that totally unacceptable,” he said.

“We need to learn from this episode and act quickly to fix the flaws in our system because our security is at stake and lives are at stake,” he said in a statement from Hawaii, where he is holidaying with his family.

Mr Obama said the concerns of the suspect's father, expressed to US officials in his native Nigeria, had been passed to the US authorities “weeks ago''.

“Weeks ago, this information was passed to a component of our intelligence community but was not effectively distributed so as to get the suspect’s name on a no-fly list,” he said.

But he said, even without that warning, the US had enough material to have ensured Abdulmutallab would not have been free to fly.