)
Malaysian Prime Minister Najib Razak flew to Australia for briefings on the search for the missing plane and talks with his Australian counterpart, Tony Abbott, whose country is overseeing the hunt in a huge and remote patch of the Indian Ocean.
"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," Abbott said in a media appearance with Najib.
No trace of the Boeing 777 has been found nearly four weeks after it vanished in the early hours of March 8 on a flight from Kuala Lumpur to Beijing with 239 people on board.
Ten planes and nine ships were involved in search operations yesterday, scouring the ocean far off Australia's southwest corner where investigators believe the plane may have ended up after unknown events occurred on board.
More resources will be committed to the wreckage hunt on Friday, with 14 planes and nine ships to search a 217,000 square kilometre expanse 1,700 kilometres northwest of Perth, the Joint Agency Coordination Centre overseeing the search said.
JACC described weather in the search area as fair, with visibility about 10 kilometres and cloud above the optimum search altitude of 1,000 feet.
Najib, whose government has been harshly criticised by some victims' families for giving sometimes conflicting information about the flight and for the slow pace of the investigation, said everyone involved in the search is thinking of the families of victims who are waiting desperately for news.
"I know that until we find the plane, many families cannot start to grieve," Najib said. "I cannot imagine what they are going through. But I can promise them that we will not give up.
"We want to provide comfort to the families and we will not rest until answers are indeed found. In due time, we will provide a closure for this event," he said.
Najib met with Abbott at the Australian base near Perth that is serving as the hub for the multinational search effort. They were briefed by Angus Houston, the head of a joint agency overseeing the search.
