French gendarmes and police stand near a large piece of plane debris which was found on the beach in Saint-Andre, on the French Indian Ocean island of La Reunion, in this picture taken July 29, 2015. [Photo/Agencies]

KUALA LUMPUR - Malaysia confirmed early on Thursday that a piece of a wing washed up on an Indian Ocean island beach last week was from Malaysian Airlines flight MH370, the first trace of the plane found since it vanished last year with 239 people on board.

"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," Prime Minister Najib Razak said in an early morning televised address.

"I would like to assure all those affected by this tragedy that the government of Malaysia is committed to do everything within our means to find out the truth of what happened," Najib said.

The announcement, by providing the first direct evidence that the plane crashed in the ocean, closes a chapter in one of the biggest mysteries in aviation history, but gives victims' families little clue as to why it disappeared.

"It's not the end," said Jacquita Gonzales, who lost her husband Patrick Gomes, a flight attendant.

"Although they found something, you know, it's not the end. They still need to find the whole plane and our spouses as well. We still want them back," she said.

The airline described the discovery as "a major breakthrough for us in resolving the disappearance of MH370.

"We expect and hope that there would be more objects to be found which would be able to help resolve this mystery," it said in a statement issued as soon as Najib had spoken.