President Barack Obama praised the new September 11 museum as "a sacred place of healing and of hope" that captures both the story and the spirit of heroism and helping others that followed the attacks.

US President Barack Obama and first lady Michelle Obama have toured the September 11 museum, viewing a memorial wall with photos of victims and a mangled fire truck.

A staircase at the World Trade Centre that proved a lifeline for countless September 11 escapers and survived the devastation will be moved from the site his weekend.