As the dust settles on the announcement that the US government, nearly 10 years after the attacks on New York, managed to assassinate Osama bin Laden, details have emerged of the successful strike on the al-Qaeda leader.

A team of elite American commandos slid down ropes from helicopters into the compound where Osama bin Laden was hiding before shooting him in the head when he opened fire on them, US officials revealed.

Acting on intelligence that bin Laden was holed up in a compound in the city of Abbottabad, US President Barack Obama ordered the unilateral mission to capture or kill him on foreign soil early on Monday morning.

US Black Hawk and Chinook helicopters ferried about two dozen troops from Navy Seal Team Six, a top military counter-terrorism unit, into the fortified compound north of Islamabad, the Pakistani capital.

The US$1m property had been identified by the CIA as bin Laden’s hideout last August after years of monitoring one of the terrorist leader’s couriers.

The convoy of helicopters travelled from an airbase in north-west Pakistan and dropped the elite team at the destination at 1am local time on Monday.

White House counter-terrorism adviser John Brennan said the ‘minutes passed like days’. He added: ‘It was probably one of the most anxiety-filled periods of time in the lives of the people assembled here yesterday. The president was very concerned about the security of our personnel.

‘It was clearly very tense, with a lot of people holding their breath and a fair degree of silence as it progressed.’

Earlier, the Obama administration insisted bin Laden would have been captured alive had he surrendered.

‘This was a kill operation,’ a US official said but added: ‘If he had waved a white flag of surrender, he would have been taken alive.’

Wearing night-vision goggles, the unit dropped into the high-walled compound by sliding down ropes from the helicopters in the overnight raid which lasted 40 minutes, officials said.

Senior US officials said bin Laden was killed towards the end of a firefight in a building at the fortified compound, which is just 800 metres from the Kakul Military Academy.