Malaysia said on Thursday paint color and maintenance-record matches proved that a piece of wing found on the shore of an Indian Ocean island was part of the wreckage of Malaysian Airlines flight MH370, which vanished without trace last year.
Transport Minister Liow Tiong Lai said investigators on the French island of Reunion had collected more aircraft debris, including a plane window and aluminium foil, but there was no confirmation they also belonged to the missing plane.
With the first trace of the plane now confirmed, Malaysia has asked the governments of neighboring Mauritius and Madagascar to help widen the search area, he told reporters.
Earlier, Prime Minister Najib Razak confirmed that the piece of debris was from the Boeing 777 airliner that was bound for Beijing from Kuala Lumpur with 239 passengers and crew on board when it went missing.
"Today, 515 days since the plane disappeared, it is with a heavy heart that I must tell you that an international team of experts have conclusively confirmed that the aircraft debris found on Reunion Island is indeed from MH370," Najib said in a televised address.
The airline described the find as "a major breakthrough".
The first piece of direct evidence that the plane crashed in the ocean closed a chapter in one of the biggest mysteries in aviation history.
But exactly what happened remains unknown and Najib's announcement did not appear to represent any kind of resolution for the families of those on board, most of whom were Chinese.
The fragment of wing known as a flaperon was flown to mainland France after being found last week covered in barnacles on a beach on Reunion.
Despite the Malaysian confirmation, prosecutors in France stopped short of declaring they were certain, saying only that there was a "very strong presumption".
Paris Prosecutor Serge Mackowiak said this was based on technical data supplied by both the manufacturer and airline but gave no indication that experts had discovered a serial number or unique markings that would put the link beyond doubt.
Representatives of manufacturer Boeing confirmed that the flaperon came from a 777 jet, he said, and Malaysia Airlines provided documentation of the missing aircraft.
Mackowiak told reporters in Paris more analysis would be carried out on Thursday, and a fragment of luggage also found in Reunion would be examined by French police.
"We appreciate the French team and their support and respect their decision to continue with the verification," Liow said, adding that Malaysian experts were convinced the flaperon was from MH370 because a seal on the part matched a maintenance record and the paint was the same color.