Australia "won't rest" until everything possible is done to locate the missing Malaysian Airlines flight MH370, Prime Minister Tony Abbott said Sunday.
He said there was no limit yet on the international search operation in the Indian Ocean being coordinated from Perth.
Australia would spend "what it needs to spend" to seek a solution to the mystery of what happened to the plane and its 239 passengers and crew that disappeared more than three weeks ago, he said.
Abbott named former military chief retired Air Chief Marshal Angus Houston to head a new joint agency in Perth to coordinate the search currently focused on an area 1,850 kilometres west of the continent.
Malaysia will continue to hold primary responsibility for the recovery operation and the investigation into why the plane made a radical change of course toward the Indian Ocean while flying from Kuala Lumpur to Beijing on March 8.Ten aircraft from Australia, Malaysia, Japan, China, South Korea, New Zealand and the United States and 10 ships are engaged in a search area roughly the size of Poland.
An Australian navy ship is expected to leave Perth Monday with special a US device that can be towed behind the ship to locate any signal from the plane's flight data and voice recorders.
If they do locate the signal an unmanned underwater drone can be lowered to try to find the instruments which could shed light on the mystery.
US Navy Captain Mark Matthews said the battery-powered electronic signal emitter on the plane's "black boxes" could last up to 15 days beyond its 30-day minimum life.
The locator can detect the signal to a depth of 6 kilometres.
The ship tows the equipment at just 5 knots, so finding a potential crash site soon is vital.
"We don't have a defined search area yet. We have our challenges in front of us," Matthews said.
The Australian Maritime Safety Authority said objects scooped from the sea Saturday in the search area by Chinese and Australian ships had turned out to be fishing gear and rubbish.
Nothing has been found so far to confirm the search area is where the plane went down. It was chosen from calculations about last known recorded positions of the airplane as it headed south into the Indian Ocean.