Debris found on the Indian Ocean island of Reunion is to be taken to France to find out whether it is from the missing airliner MH370.
Malaysia's prime minister Najib Razak said initial reports suggested the 2-metre long wreckage was very likely to be from a Boeing 777 and the location was "consistent with the drift analysis provided to the Malaysian investigation team".
Malaysia Airlines' flight MH370 went missing in March 2014 with 239 people on board shortly after take off from the Malaysian capital Kuala Lumpur en route to China on 8 March 2014.
It is the only Boeing 777 to have disappeared over the ocean.
Investigators expect to take at least a day before they can confirm whether debris is from the missing plane.
Radio New Zealand's correspondent in Paris, Hugh Schofield, told Morning Report identification should happen quite quickly.
"There's all these serial numbers, which people keep talking about, which should exist on the piece of debris, we know that some numbers have been found already. I think that's going to be quite swift, that part of it.
"If it is from the plane then we will go to the next stage with the debris, which is getting is tell us what it can about what happened."
Mr Schofield said a French navy boat and helicopter were in the area searching for further debris.
Oceanographer David Griffin, of Australia's national science agency, told the BBC that the location of the find was "consistent with where we think debris might have turned up".
There were 239 passengers and crew on board the plane when it went missing.
Mr Najib said French authorities were taking the debris to the southern French city of Toulouse - the site of the nearest office of the French body responsible for air accident investigations (the BEA) - to verify it as quickly as possible.
He said the location of the debris was consistent with drift analysis provided to Malaysian investigators.
"As soon as we have more information or any verification we will make it public. I promise the families of those lost that whatever happens, we will not give up."
Malaysia has sent a team of investigators and other officials to Toulouse and another team of experts to Reunion - a French overseas department.
The BBC's Chris Bockman in Toulouse says French aviation authorities have a huge hangar facility in the city to store and study wreckage, as they did with the Air France airliner that crashed on its way from Brazil to Paris in 2009.
Aviation experts who have studied photos of the debris, found on Wednesday, said it resembled a flaperon - a moving part of the wing surface - from a Boeing 777.
On Thursday, a municipal employee also found what appeared to be part of a damaged suitcase on the Reunion coast, according to local media (in French).
Dr Simon Boxall, an oceanographer from the UK's University of Southampton, told the BBC that the search for debris could also now include the coasts of Madagascar and South Africa, west of Reunion.
"The key piece of information is still going to be sitting with the black boxes on the sea floor," he said.
Search efforts for MH370, led by Australia, are focused on an area west of the Australian city of Perth - about 4,000km east of Reunion.
The Australian government has described the discovery of the wreckage as "a very significant development".
After MH370 disappeared from radar screens, experts analysed data from faint "pings" the aircraft sent to satellites to narrow down its possible location.
More than half of those on board the plane were Chinese citizens.
A spokesperson for China's foreign ministry said: "We have noticed the reports and are wasting no time in obtaining and checking the information."
A group of relatives of many of the Chinese passengers said in a statement that they wanted "100%" certainty about where the part is from, and that the search for the airliner should continue.