Australian officials defended their suspension of the fruitless deep-sea sonar search for Malaysia Airlines Flight 370, insisting on Wednesday that the enormous costs involved played no role in their decision to halt the nearly three-year hunt.

Australia’s Transport Minister Darren Chester also said that while the search had been called off on Tuesday, work behind the scenes would go on, with experts continuing to analyze data associated with the doomed aircraft’s final hours and examining any future debris that washes ashore. But he declined to specify what kind of breakthrough would convince officials to resume the search for the Boeing 777’s underwater wreckage.

“When we get some information or data or a breakthrough that leads us to a specific location, the experts will know it when they see it,” he told reporters in the southern city of Melbourne.

Australia, Malaysia and China — which have funded the $160 million search — have rejected pleas from family members of the passengers and some investigators that search crews be allowed to keep going. China is involved because more than half of the 239 people on board the plane were Chinese.

Late last year, as ships with high-tech search equipment covered the last strips of the 120,000-square kilometer (46,000-square mile) search zone west of Australia, experts concluded they had been looking in the wrong place and should have been searching a smaller area immediately to the north. But by then, the three countries had already agreed not to search elsewhere without evidence of the plane’s exact location.

Chester defended the decision to call off the hunt without checking the new area to the north, saying, “No one is coming to me as minister and saying, ‘We know where MH370 is.'” And he insisted the high price of the search had nothing to do with pulling the plug.

“It is a costly exercise, but it hasn’t been the factor which led to the decision to suspend the search,” Chester said. “We don’t want to provide false hope to the families and friends. We need to have credible new evidence leading to a specific location before we would be reasonably considering future search efforts.”

Officials are facing a no-win situation, the transport minister said in an interview with the Australian Broadcasting Corp. Call off the search, he said, and disappoint those who want resolution to the world’s greatest aviation mystery. Keep going, and face the wrath of taxpayers who have already spent millions of dollars with no result.

The new 25,000-square kilometer (9,700-square mile) area to the north was determined with the help of drift modeling by Australia’s Commonwealth Scientific and Industrial Research Organization, which attempted to calculate where debris that has washed ashore on coastlines in the western Indian Ocean originated.

Chester said that drift modeling would continue, and experts will scrutinize any further debris that washes up. Investigators will also continue to refine the satellite data that led them to conclude the plane went down somewhere in the Indian Ocean after it vanished on a flight from Kuala Lumpur to Beijing on March 8, 2014.

Australian Prime Minister Malcolm Turnbull said he empathized with the families who want the search to go on, but said officials had done the best they could under extraordinary circumstances.

“We share their deep disappointment that the plane has not been found,” Turnbull told reporters. “It is an unprecedented search. It’s been conducted with the best advice over the areas that were identified as the most likely to find the location of the airplane. It is a shocking tragedy and we grieve and we deeply regret the loss and we deeply regret that the plane has not been found.”

Tony Abbott, who was Australia’s prime minister when the Boeing 777 disappeared, suggested the search should continue. Abbott pledged on the first anniversary of the tragedy: “It can’t go on forever, but as long as there are reasonable leads, the search will go on.” On Tuesday, he tweeted: “Disappointed that the search for MH370 has been called off. Especially if some experts think there are better places to look.”

If the plane is never found, the reasons for its disappearance and crash will probably never be known, though Malaysia has said the plane’s erratic movements after takeoff were consistent with deliberate actions.

Chester said he had not given up hope of resolution — though he conceded answers may be a long way off.

“It’s an extraordinary aviation mystery as it stands today,” he said. “I’m hopeful that we have a breakthrough in the future. We need to prepare ourselves for the sad and tragic reality that in this foreseeable future, we may not find MH370.”

(AP)