MH370: Robotic submarine completes 3rd search mission

However, the Australian Prime Minister did not elaborate on what the new phase may be.

Meanwhile, Malaysia's Transport and Defence Minister Hishammuddin Hussein today warned that the cost of the search for the plane's wreckage will be "huge".

"When we look at salvaging (wreckage) at a depth of 4.5 kilometres, no military out there has the capacity to do it," Hishammuddin told reporters in Kuala Lumpur.

"We have to look at contractors, and the cost of that will be huge," he said.

The aerial and sea search for the plane continued today with up to 10military aircraft, two civilian plane and 11 ships taking part in the operations.

The Beijing-bound plane carrying 239 people, including five Indians, an Indo-Canadian and 154 Chinese nationals - had mysteriously vanished on March 8 after taking off from Kuala Lumpur.

Using satellite data, officials have concluded that it ended its journey in seas west of Perth.

They do not know why the plane flew so far off course and an investigation is ongoing. Finding the plane's flight recorders are seen as key to understanding what happened.

The Bluefin-21, operated by the US Navy off the Australian vessel Ocean Shield, is an autonomous underwater vehicle (AUV) that can identify objects by creating a sonar map of the sea floor.

The underwater vehicle had aborted its second mission due to a technical trouble before it could finally complete its full mission in a third attempt.