On Monday, the Australian Defence Force said it had dispatched an RAAF AP-3C Orion aircraft from Darwin to assist with the Indonesian-led search.

"Our focus at this point must be on finding the plane... at this stage we are just hoping and praying that some passengers and crew can be rescued," Ms Bishop said.

But she warned that "as time goes on" fears about the fate of the 162 passengers and crew would likely be confirmed.

Defence Force Chief Mark Binskin said the P3 Orion has "a well-proven capability" in search and rescues and carries maritime search radar, infra-red technology and electro-optical sensors.

Ms Bishop said Singapore had also provided support for the search effort given it was the country where the plane was originally due to land after its departure from Indonesia.