President Barack Obama designated the search for a missing Malaysian passenger jet a "top priority" for the United States as Malaysia shared evidence with the FBI and sought Thursday to pacify relatives' anger at the lack of progress.
Nearly two weeks after Malaysia Airlines flight 370 vanished with 239 passengers and crew on board, no concrete evidence has been uncovered to confirm what happened, who was responsible or -- most importantly -- where the aircraft ended up.
In his first on-camera comments on the mystery, Obama, who is due to visit Malaysia next month, offered thoughts and prayers to the anguished relatives of the missing passengers.
"I want them to be assured that we consider this a top priority," he said in a television interview at the White House.
Nearly two-thirds of those on board the Beijing-bound flight were Chinese, and there were chaotic, emotional scenes Wednesday when a handful of tearful Chinese relatives tried to gatecrash Malaysia's tightly controlled daily media briefing at a hotel near Kuala Lumpur airport.
Shouting and crying, the relatives unfurled a protest banner reading "Give us back our families", and accused the Malaysian authorities of withholding information and doing too little to find the plane.
Obama stressed there had been "close cooperation" with the Malaysian government and added that the United States had put "every resource that we have available" at the disposal of the search process.
There were three US nationals, including an infant, on board.
- Data deleted -
A US official who spoke to AFP on condition of anonymity said Malaysia had asked the FBI to help recover data deleted from a flight simulator in the home of the missing plane's chief pilot, Captain Zaharie Ahmad Shah.
Malaysian police removed the simulator from Zaharie's home on Saturday, after investigators said they believed the Boeing 777 had been deliberately diverted from its intended route by someone on board.
The New York Times quoted a senior US law enforcement official as saying FBI agents in Kuala Lumpur would likely make copies of the simulator's hard drive and send the contents back to analysts in the United States who specialise in retrieval of deleted computer data.
"Right now, it's the best chance we have of finding something," that official said.
Zaharie, a 33-year veteran of the airline, was highly regarded by his peers. But suspicion has clouded him since investigators concluded the plane's communication systems were likely disabled manually and the aircraft diverted by a skilled aviator.
Background checks on the plane's 227 passengers have so far failed to uncover any relevant information.
In the days immediately after the jet vanished, FBI agents were reportedly kept at arm's length by Malaysian authorities.
But with the search area now encompassing vast tracts of land and sea equivalent to the entire land mass of Australia, Malaysia has sought the help of more than two dozen countries.
Australia said Wednesday that the search corridor in the southern Indian Ocean had been "significantly refined" following closer analysis of flight MH370's fuel reserves, and the Indian Navy said it had been given fresh search coordinates.
- Screaming relatives -
There was a noticeably tighter security presence at the airport hotel where Wednesday's protest by angry Chinese relatives played out in front of the gathered international media.
Several police officers guarded the entrance to the Sama Sama Hotel and new barriers were erected restricting access to the area around the briefing room.
One hotel official told AFP that police had briefed hotel security on preventing "suspicious people" from entering.
Wednesday's ugly scenes of screaming women being forcibly carried from the briefing room only compounded the pressure on the Malaysian authorities, who argue they are doing everything possible to resolve one of the biggest mysteries of the modern aviation era.
"I fully understand what they're going through. Emotions are high," said the minister of defence and transport, Hishammuddin Hussein.
He added that a "high-level" Malaysian team also would be sent to Beijing to deal with increasingly agitated relatives there.
The clock is ticking down on the 30 days during which the aircraft black box will transmit a signal.
The search has been hampered by the reluctance of some countries to share sensitive radar and satellite data, and to allow surveillance planes into their airspace.
Peter Weeks, whose brother Paul, 39, was on the plane, said there had been no official communication from any government figures in Malaysia.
"The information we get is no better than what is in the media," he told CNN.
"You spend 24 hours a day thinking about it really; every waking moment and even the few moments of sleep you get.
"There's no solid information about anything," he said.