Search for missing jet most difficult in history: Australian PM

Australian Prime Minister Tony Abbott said Thursday that the ongoing search for missing Malaysia Airlines flight MH370 is ''the most difficult in human history'', while reiterating his promise to the families of those on board that his country will continue the current search process as best as they can.

In a joint press conference with his visiting Malaysian counterpart Najib Razak, Abbott told reporters this was probably the most difficult search ever undertaken, but "as far as Australia is concerned, we are throwing everything we have" to search the aircraft, Xinhua reported.

"This is a very tough time for Prime Minister Najib... the search area is moving north, but it's still a remote and inaccessible area... it's the most difficult in human history," said the Australian leader.

He also asked the families of those on board the lost jet to be "patient", saying Australia and the multinational forces will not let them down and would provide the warmest possible welcome if they wanted to come to Australia.

Meanwhile up to eight planes and nine ships have been pressed into service for Thursday's search for the missing jet.

"The Australian Maritime Safety Authority has determined a search area of about 223,000 Sq km, 1,680 km west northwest of Perth," Australia's Joint Agency Coordination Centre (JACC), that is coordinating the multinational search, said in its latest update.

It said eight military planes would assist in the search and one of these planes would be tasked to drop self locating datum marker buoys within the search area.

"The weather forecast for today's (Thursday's) search is fair, with visibility approximately 10 km, however the southern area may experience some isolated showers," the JCC update said.

"The Australian Transport Safety Bureau continues to refine the area where the aircraft entered the water based on continuing ground-breaking and multi-disciplinary technical analysis of satellite communication and aircraft performance, passed from the international air crash investigative team comprising analysts from Malaysia, the United States, the UK, China and Australia."

Malaysia Airlines flight MH370 vanished mysteriously about an hour after taking off from Kuala Lumpur shortly after midnight March 8.

The Boeing 777-200ER was scheduled to land in Beijing the same day. The 227 passengers on board included five Indians, 154 Chinese and 38 Malaysians.