Malaysian prime minister Najib Razak said his government is committed to solving the "agonising mystery" of Flight 370 as the country marks the second anniversary of the aircraft's disappearance.
Vessels looking for the Malaysia Airlines jet are due to finish scouring 120,000 square kilometres of southern Indian Ocean by mid-2016.
If that search fails, officials from Malaysia, Australia and China will gather "to determine the way forward," Mr Najib said in a statement on Tuesday.
The Boeing 777 that vanished from radar on March 8th, 2014, en route to Beijing from Kuala Lumpur has become modern aviation's biggest mystery. There has been no trace of the 239 people on board.
Families of the victims, more than half of whom were Chinese, want the hunt to continue even if the current search comes up empty, while investigators say the hunt will end unless fresh clues are found.
In Beijing on Tuesday, about 30 relatives marked the day by praying at Lama Temple, one of the city’s most historic sites.
Many families don’t believe their loved ones are dead because no bodies have been recovered. Outnumbered by police, they chanted, “We won’t give up until you return my family members.” Some held placards showing a picture of a plane with the words, “Definitely will return peacefully.”
Authorities still have little idea what took place in the cockpit or why the plane flew off course.
Last week, investigators began examining an object found on the coast of Mozambique that they suspect could be from the missing plane.
If verified, that washed-up fragment would be only the second component ever found from MH370.
A barnacle-encrusted wing piece was discovered on Reunion Island in July 2015. The same resident who found that part came across another piece on Reunion last week, made of similar material, and turned it over to police, according to Agence France-Presse.
Thousands of miles to the east, the main search for the jet centers on a remote patch of Indian Ocean. About 90,000 square kilometers, or three-quarters of the area, have been scanned without success, the Australian government said Tuesday.
“The search has been the most challenging in aviation history,” Mr Najib said in his statement.
He said he was still “hopeful” the jet would be found in that area.
Analysis of ocean drift indicates debris from the crash could have reached the coast of Mozambique, the government said.
Two years ago, air-traffic controllers lost contact with MH370 less than an hour after take-off as it approached Vietnam. Military radar showed the plane took a left turn and looped back across Malaysia. Based on pings between the plane and a satellite, Australian investigators believe MH370 cruised south over the Indian Ocean before plunging into the water.
It's very unlikely that anyone was in control of the plane when it hit the ocean, Martin Dolan, head of the Australian Transport Safety Bureau, said in an interview last month.
Analysis of the satellite-communication data suggests the plane was on auto-pilot until it ran out of fuel.
It then probably banked left and spiraled into the ocean, Mr Dolan said.
A Malaysian-led investigation team is still working on conclusions and safety recommendations from the aircraft’s disappearance, according to a statement Tuesday.
Malaysia will release a final report on the disaster if wreckage is found or the search is called off, it said.
The team’s eight areas of focus are: the flight’s diversion from its planned route; air traffic services; the profiles of the crew; the plane’s airworthiness and maintenance record; satellite communications; wreckage and impact; organization and management at Malaysia Airlines and the country’s civil aviation department; and the plane’s cargo.
"The document is meaningless. It doesn't say anything new," Zhang Lixia from Heilongjiang province, whose daughter was on the flight, said at the Lama Temple.
“We want to know exactly what happened.” Some family members have sued Malaysia Airlines in the US and China over the incident.
Bloomberg