Barack Obama: 'Thoughts and prayers with families'
A US navy P-8 Poseidon aircraft will be the first to reach floating objects which may have come from Malaysia Airlines flight MH370, missing since 8 March.
Australia is investigating two objects seen on satellite images, with search planes heading to the area 2,500km (1,550 miles) south-west of Perth.
US President Barack Obama said he wanted to reassure relatives of the 239 passengers on board that locating the plane was "a top priority".