French investigators said on Monday it was too soon to consider launching undersea searches for the remains of the Malaysia Airlines jet that officials said went down in the Indian Ocean.

France's BEA accident investigation service, which had sent three investigators to Kuala Lumpur, said the "extremely vast areas (involved) do not make it possible at this stage to consider undersea searches.

The announcement came in the hours that followed word from Malaysian Prime Minister Najib Razak that Malaysian Airlines flight MH370 "ended in the southern Indian Ocean."

This apparent solution of the enigma of whether the plane had in fact crashed came courtesy of analysis of satellite data done by British firm Inmarsat. MH370 went missing on March 8th en route from Kuala Lumpur to Beijing with 239 people aboard

"Based on their new analysis, Inmarsat and the UK Air Accidents Investigations Branch have concluded that MH370's…last position was in the middle of the Indian Ocean, west of Perth," the prime minister's statement said.

"This is a remote location, far from any landing sites. It is therefore with great sadness that I must inform you that, according to this new data, flight MH370 ended in the Southern Indian Ocean," he continued.

Malaysia, which later revealed the plane turned back over the Malaysian peninsula after losing contact, has enlisted 25 other countries to help hunt for the plane.

Efforts in recent days have focused on the coast off Australia after previous satellite images of large objects there were released, and a plane spotted a wooden cargo pallet, along with some belts or straps.

It said its investigators, who had returned from Kuala Lumpur at the weekend, had discussed possible techniques for undersea searches with Malaysian authorities.

In particular they discussed "their experience… acquired during then search between 2009 and 2011 for the wreckage of Rio-Paris flight AF447," it said.

It took 23 months for BEA investigators to find the wreckage of the Air France flight after it went down in the Atlantic in 2009.

Malaysia on Monday said the MH370, which went missing more than two weeks ago, crashed in the Indian Ocean, but shed no light on the mystery of why it veered from its intended course.