New satellite data analysis has confirmed that missing Flight 370 crashed into the southern Indian Ocean, Malaysia's prime minister told a news conference on Monday.
Najib Razak said flight data suggested the Malaysia Airlines Boeing 777's "last position was in the middle of the Indian Ocean west of Perth, [Australia]."
He added: “This is a remote location, far from any possible landing site. It is therefore with deep sadness and regret that according to this data the flight ended in the southern Indian Ocean.”
The prime minister said his conclusion was based on work by the U.K. Air Accidents Investigation Branch and satellite firm Inmarsat, which had been "performing further calculations on the data, using a type of analysis, never before used in an investigation of this sort."
After more than two weeks of mystery and speculation, Najib's announcement was the first official confirmation of the fate of the Boeing 777 that vanished on March 8.
“Malaysia Airlines have already spoken to the families of the passengers and crew to inform them of this development,” the prime minister added. “For them the past few weeks have been heartbreaking. I know this news must be harder still.”
The families of Flight 370's passengers were sent text messages by the airline telling them that the plane had been "lost and that none of those aboard have survived."
Selamat Omar, the father of a 29-year-old aviation engineer who was on the flight, said some members of families of other passengers broke down in tears at the news. "We accept the news of the tragedy. It is fate," Selamat told The Associated Press in Kuala Lumpur.
Earlier, an Australian plane spotted an "orange rectangular object" and a "gray or green circular object" while searching for the aircraft, officials said. They were seen around 1,550 miles southwest of Perth, Australia.
Flight 370 disappeared from civilian radar screens less than an hour after taking off from Kuala Lumpur for Beijing with 239 people on board.
Attention and resources in the search for the Boeing 777 have shifted from an initial focus north of the equator to an increasingly narrowed stretch of rough sea, thousands of miles from the plane's original flight path.
A spokeswoman for Britain's Department for Transport refused to comment on the AAIB's involvement, saying it was a “live investigation” being led by the Malaysian authorities.
In a statement, Malaysia Airlines said that the "ongoing multinational search operation will continue, as we seek answers to the questions which remain."
Jason Cumming of NBC News, Reuters and The Associated Press contributed to this report.