Officials from Malaysia, Australia and China agreed Thursday that if missing Malaysian Airlines Flight 370 is not found this spring in the current designated search area off the western coast of Australia, the zone would be expanded to double in size, and the quest could continue for another year.
Authorities are using underwater vehicles equipped with sonar to search a zone of more than 23,000 square miles, an effort expected to be finished by late spring; the work is about 60% complete.
The expanded search area would cover more than 46,000 square miles, about the size of Pennsylvania. This bigger area, in an arc sweeping from northeast to southwest, officials said, would "cover the entire highest probability area identified by expert analysis."
Searching in the expanded area, the officials said, would take up to a year because of the "adverse weather conditions in the upcoming winter months" of the Southern Hemisphere.
MH 370 vanished in March 2014 en route from Kuala Lumpur to Beijing. No trace of the jetliner, which had 239 people aboard, has been found.
Malaysia's Minister of Transport, Liow Tong Lai, met in Kuala Lumpur with Deputy Australian Prime Minister Warren Truss and China's minster of transport, Yang Chuantang.
The majority of the passengers aboard the flight were Chinese.