Australia was also consulting Malaysia, China and the US on the next phase of the search for the Malaysia Airlines Flight MH 370, that mysteriously disappeared on March 8 with 239 people on board, including five Indians.
More powerful towed side-scan commercial sonar equipment would probably be deployed, similar to the system that found the Titanic 3,800 m under the Atlantic Ocean in 1985 and the Australian second world war wreck HMAS Sydney in the Indian Ocean, north of the current search area, in 2008, the Associated Press quoted Australia's defence minister David Johnston as saying.
"The next phase, I think, is that we step up with potentially a more powerful, more capable side-scan sonar to do deeper water," he said.
Australian Prime Minister Tony Abbott said the plane's probable impact zone was a swath of sea floor 700 kms long and 80 kms wide.
He told reporters that a new search strategy would be adopted if nothing was found in the current search zone.
"If at the end of that period we find nothing, we are not going to abandon the search, we may well rethink the search, but we will not rest until we have done everything we can to solve this mystery," Abbott said.
Up to 10 military aircraft and 12 ships will assist in today's search for the Malaysia Airlines Flight MH370, a day after planned air search activities were suspended due to poor weather conditions in the search area due to Tropical Cyclone Jack.
Autonomous underwater vehicle Bluefin-21, a US Navy probe equipped with side-scan sonar, "has now completed more than 80 per cent of the focused underwater search area," Perth-based Joint Agency Coordination Centre (JACC) said in a statement.
"No contacts of interest have been found to date," it said on the 47th day of the search for the ill-fated Beijing- bound plane, that veered off from its course after take-off from Kuala Lumpur.
"Bluefin-21 AUV is currently completing mission ten in the underwater search area," the statement said.
The min-submarine has focused the search on an area where four acoustic signals were detected, leading authorities to believe that the Boeing 777-200's black box may be located there.
The AUV had less than one-fifth of the search area left to complete but that could take another two weeks, Johnston said, adding: "We want to be very thorough."
Abbott said: "Australia will not rest until we have done everything we humanly can to get to the bottom of this mystery. We may rethink the search but we will not rest until we have done all we can to solve this mystery.
"We owe it to the families of the 239 people on board, we owe it to the hundreds of millions - indeed billion - of people who travel by air to try to get to the bottom of this. The only way we can get to the bottom of this is to keep searching the probable impact zone until we find something or until we have searched it as thoroughly as human ingenuity allows at this time.
Refuting reports that the plane could have landed, Abbott said: "Our expert advice is that the aircraft went down somewhere in the Indian Ocean, we have identified a probable impact zone, which is about 700km long, about 80km wide."
Johnston said the government was tracking the cost of the search but that Australia wanted to help its friends in this "most tragic circumstance".
"Yes there are costs incurred, we want to find this aircraft," he said, adding: "We want to say to our friends in Malaysia and China that this is not about cost."
Today, the Australian Maritime Safety Authority has planned a visual search area totaling approximately 37,948 sq kms. The centre of the search area lies approximately 1,584 kilometres north west of Perth.
The weather forecast for today is for isolated showers increasing to heavy rain, widespread low cloud, with south easterly winds, sea swells up to 2.5 metres and visibility of one km. Prevailing weather conditions may affect today's air search.
The focused underwater search area is defined as a circle of 10km-radius around the second Towed Pinger Locator detection which occurred on April 8.
Finding the black box and the wreckage are crucial for knowing why the Beijing-bound plane veered off from its route and mysteriously vanished after taking off from Kuala Lumpur.
The mystery of the missing plane has continued to baffle aviation and security authorities who have so far failed to trace the aircraft despite deploying hi-tech radar and other gadgets.