Bin Laden wanted to kill Obama because he thought Joe Biden was totally unprepared to be president

Osama bin Laden planned to assassinate President Barack Obama to unsteady the United States by putting 'totally unprepared' Joe Biden in charge.

Declassified documents seized from Bin Laden's Pakistan compound as he was killed in May 2011 reveal his plans to throw the U.S. 'into a crisis' by killing Obama while he traveled in a plane with U.S. military commander David Petraeus.

The 45-page document, which were first reported by The Washington Post in 2012, is now available in full along with hundreds of others from the raid.

Osama wrote to Al Qaeda deputy Atiyah Abd al-Rahman: 'The reason for concentrating on them is that Obama is the head of infidelity and killing him automatically will make [Vice President] Biden take over the presidency, Biden is totally unprepared for that post, which will lead the U.S. into a crisis.

'As for Petraeus, he is the man of the hour ... and killing him would alter the war's path' in Afghanistan.'

Osama's ambition was to have Ilyas Kasmiri, described by U.S. officials as Al Qaeda's military operations chief in Pakistan, shoot down the plane carrying Obama.

The aspirations never developed into further planning, the U.S. intelligence service told The Washington Post.