CANBERRA - The search for missing Malaysia Airlines Flight MH370 cannot go on forever, Australia's deputy prime minister said, and discussions are already under way between Australia, China and Malaysia as to whether to call off the hunt within weeks.
No trace has been found of the Boeing 777 aircraft, which disappeared a year ago this week carrying 239 passengers and crew, in what has become one of the greatest mysteries in aviation history.
MH370 vanished from radar screens shortly after taking off from Kuala Lumpur, bound for Beijing, early on March 8. Investigators believe it was flown thousands of miles off course before eventually crashing into the Indian Ocean.
The search of a rugged 60,000 sq km (23,000 sq mile) patch of sea floor some 1,600 km (1,000 miles) west of the Australian city of Perth, which experts believe is the plane's most likely resting place, will likely be finished by May.
Australian Deputy Prime Minister Warren Truss said that a decision would have to be taken well before then as to whether to continue into the vast 1.1 million sq km area around the primary search zone if nothing has been found.
Discussions had already begun about what to do in that event, including the possibility that the search might be called off, said Truss, who is also transport minister.
"For many of the families onboard, they won't have closure unless they have certain knowledge that the aircraft has been located and perhaps their loved ones' remains have been recovered," Truss said in an interview.
"We clearly cannot keep searching forever, but we want to do everything that's reasonably possible to locate the aircraft."
Truss compared the search, already the most expensive of its kind, with another great mystery from an earlier era, the hunt for missing aviation pioneer Amelia Earhart, who disappeared in 1937 during an early attempt to circumnavigate the globe.
Four vessels owned by Dutch engineering firm Fugro , equipped with sophisticated underwater drones, have searched about 40 percent of the previously unmapped expanse of sea floor that has been designated the highest priority.