PERTH, Australia — Leaders of the two countries heading multinational efforts to solve the mystery of Malaysia Airlines Flight 370 pledged Thursday that no effort will be spared to give the families of those on board the answers they need.
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 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 Thursday, scouring the ocean far off Australia's southwest corner where investigators think the plane may have ended up after unknown events occurred on board.
More resources will be committed to the search today, with 14 planes and nine ships to cover an 84,000-square-mile area 1,100 miles northwest of Perth, the Joint Agency Coordination Center overseeing the search said.
Najib, whose government has been harshly criticized 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 who are waiting desperately for news.
"I can promise them that we will not give up," Najib said. "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."