Australia PM suggests MH370 search could be scaled back

The Malaysia Airlines plane disappeared en route from Kuala Lumpur to Beijing on March 8, 2014 with 239 people on board. No trace has been found despite a massive surface and underwater hunt.

"I do reassure the families of our hope and expectation that the ongoing search will succeed," Abbott told parliament in Canberra.

"I can't promise that the search will go on at this intensity forever but we will continue our very best efforts to resolve this mystery and provide some answers."

Australia is leading the search in the Indian Ocean some 1,600 kilometres (1,000 miles) off its west coast, with four ships using sophisticated sonar systems to scour a huge underwater area.

The vessels are focusing on a 60,000 square kilometre (23,000 square mile) priority zone, with the hunt scheduled to end in May.

The intensive search -- jointly funded by Australia and Malaysia with a budget of Aus$120 million (US$93 million) -- has so far only turned up a few shipping containers.

The agency coordinating the search, the Australian Transport Safety Bureau, has previously said a decision on continuing after the current hunt was completed was up to the Australian and Malaysian governments.

Abbott said the plane's disappearance "demonstrated a fundamental gap in tracking long-haul flights, particularly over the oceans".

Australia, together with its neighbours Malaysia and Indonesia, plan to trial a "world first" system that increases the tracking of aircraft over remote oceans to a minimum rate of every 15 minutes from current intervals of 30 to 40 minutes.

"While it is not a complete answer, it will deliver a immediate improvements in the way we track aircraft while more comprehensive solutions are developed and implemented," Abbott said of the system, which was announced on Sunday.