The disappearance of Malaysia Airlines Flight MH370 has been officially declared an "accident" and the search for survivors has been called off, authorities said Thursday.

A statement released by Malaysia's Department of Civil Aviation said that all 239 people aboard the Boeing 777 were now presumed dead.

"It is therefore, with the heaviest heart and deepest sorrow that, on behalf of the government of Malaysia, we officially declare Malaysia Airlines Flight MH370 an accident," said Azharuddin Abdul Rahman, director general of Malaysia’s Department of Civil Aviation. "All 239 of the passengers and crew on board MH370 are presumed to have lost their lives."

The underwater search for wreckage in the Southern Indian Ocean will continue.

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Rahman acknowledged that the announcement would "be very difficult for the families and loved ones," but said it would enable victims' relatives to begin the process of claiming compensation.

Malaysia Airlines commercial director Hugh Dunleavy said in November that next of kin would be compensated "once we've had an official loss recorded."

Most of the passengers aboard the flight were Chinese and Beijing's foreign ministry spokeswoman Hua Chunying called on Malaysian officials to "earnestly fulfill their compensation responsibilities."

Malaysia's announcement comes more than 10 months after MH370 vanished en route from Kuala Lumpur to Beijing on March 8, 2014. The U.S. has been among 25 countries to send aircraft, ships and personnel to attempt to recover the jet, which investigators believe crashed in the Southern Indian Ocean.

Rahman described what he said was "a frustrating time for all who have tried their best in the search for MH370." He said the authorities have "never wavered in our commitment to continue our efforts to find" the airliner. "Its passengers and its crew will always be remembered and honored," he added.

"The governments of Malaysia, China and Australia have spared no expense and resources in the search for MH370," Rahman said. "This has been done with the paramount aim to find the aircraft and to seek answers. It has been done in hope of bringing some solace to the families of the passengers and crew on board MH370."

The statement highlighted that international aviation law "states that the definition of the term 'accident' includes 'the aircraft is missing.' It also states that 'an aircraft is considered to be missing when the official search has been terminated and the wreckage has not been located.'" It added that "search" is defined as "an operation to locate persons in distress" before formally declaring the disappearance an accident.

Although no trace of the aircraft has been recovered, radar and satellite data suggested the jet ran out of fuel over the Southern Indian Ocean and that the aircraft was "on the sea floor," according to Rahman. "This is a remote location, far from any possible landing sites. It is also an area with adverse sea conditions," he said. "After 327 days and based on all available data ... survivability in the defined area is highly unlikely."

The initial search involving 65 aircraft and 95 ships from 13 countries uncovered no trace of MH370. Investigators are now using underwater drones to build a map of the sea floor. So far they have mapped an area of more than 80,000 square miles — roughly the size of Kansas.

Reuters contributed to this report.