PERTH, Australia - Malaysian Prime Minister Najib Razak vowed Thursday "we will not rest" until the fate of Flight MH370 is known, as Australia called it "the most difficult search in human history". Najib toured the military base in Perth being used as a staging post in the hunt for the Malaysia Airlines plane carrying 239 people that is believed to have crashed in the Indian Ocean, and pledged never to give up looking for answers.
"We want to find answers. We want to provide comfort to the families and we will not rest until answers are indeed found," he said, as he thanked those involved in the eight-nation search.
Despite extensive scouring of the remote southern Indian Ocean off Perth, no debris that would indicate a crash site has so far been found.
Najib admitted the exhaustive hunt for the Boeing 777 that vanished on March 8 was a "gargantuan task" but said he was confident the baffling disappearance would be solved.
"I am very confident with the level of professionalism... that indeed in due time we will provide a closure to this event, on this tragedy," he said.
Kuala Lumpur's handling of the crisis has been widely criticised, especially by distraught relatives of the 153 Chinese nationals aboard.
Adding to the frustration for families affected, Malaysian police chief Khalid Abu Bakar said Wednesday a criminal investigation into what caused the flight to veer from its intended route between Kuala Lumpur and Beijing had so far been inconclusive.
In contrast, Australia's mobilisation since it was handed increased responsibility in the search effort has been praised.
Australia has far more experience than Malaysia of rescue operations, routinely monitoring huge tracts of ocean, but Prime Minister Tony Abbott said the current search was the toughest ever.
"Every day, working on the basis of just small pieces of information, we are putting the jigsaw together. And every day we have a higher degree of confidence that we know more about what happened to this ill-fated flight," he said.
"It is a very difficult search, the most difficult in human history, but as far as Australia is concerned we are throwing everything we have at it."