(CNN) -- The search for the missing Malaysia Airlines plane will be entering a new phase that will use private contractors and may cost about $60 million, Australian Prime Minister Tony Abbott said Monday.
"I regret to say that thus far none of our efforts in the air, on the surface or under sea, have found any wreckage," he said.
The new phase will focus on searching the ocean floor over a much larger area -- 60,000 square kilometers, a process that will take about six to eight months.
"We do not want this crippling cloud of uncertainty to hang over this family and the wider traveling public," he said.
It is "highly unlikely" that any debris will be found on the ocean surface, Abbott said. By this time, most of the debris will have become waterlogged and will have submerged, he said. As such, authorities will be suspending aerial searches.
Words of praise
Malaysia's government has been widely criticized over its handling of the search for missing Malaysia Airlines Flight 370 and disclosures of its investigations. But on Sunday, U.S. President Barack Obama had words of praise during a visit to the southeast Asian country.
He said the Malaysian government has been "forthcoming" with the United States about the information it has.
"The Malaysian government is working tirelessly to recover the aircraft and investigate exactly what happened," Obama told reporters. He reiterated that the United States would continue to aid in the search and offered condolences to loved ones of those lost.
Narrowed search nears end
Obama's visit came as the initial search by the Bluefin-21 neared its end.
The submersible, which is on contract to the U.S. Navy, had been scouring the ocean floor for traces of the plane.
Previously, another device, a towed pinger locator, detected signals that officials believed were from the jet's flight recorders, which determined the current search area for the Bluefin.
The plane disappeared on March 8 after leaving Kuala Lumpur, Malaysia, for Beijing.
Malaysian Prime Minister Najib Razak has said a preliminary report on the plane's disappearance will be available to the public next week.
He also asked an internal investigation team to look into what other information may be released publicly next week, his office said.
The report has been sent to the International Civil Aviation Organization, the U.N. body for global aviation, but not yet made available to the public.
The U.N. organization said among the safety recommendations in the report is a suggestion by Malaysia that the aviation world needs to look at real-time tracking of commercial aircraft.
It's the same recommendation that was made after Air France Flight 447 went down in the Atlantic Ocean in 2009.
"Anytime there is a tragedy like this, we ought to also reflect on what can be done going forward to prevent something similar from happening again," Obama said.
"That discussion has begun in Malaysia and around the world, and we'll see what improvements might be recommended to continue improving aviation security. One thing is already clear, however, is that large international efforts like this search operation benefit from existing partnerships among nations."
CNN's Elizabeth Joseph, Mike Ahlers, Sumnima Udas, David Molko, Catherine E. Shoichet and John Berman contributed to this report.