Australian Deputy Prime Minister Warren Truss on Thursday (May 29) said officials remained confident the missing Malaysia Airlines jet is somewhere in southern Indian Ocean despite searchers saying wreckage was not on the seabed in the area they had identified.

“The Australian Transport Safety Bureau has now advised that the search in the vicinity of the acoustic detections can be considered complete and in its professional judgement the area can now be discounted as the final resting place for MH370,” Truss, who is also the transport minister, told the Australian parliament.

The search was narrowed last month after a series of acoustic pings thought to be from the plane’s black box recorders were heard near where analysis of satellite data put its last location, some 1,600 km (1,000 miles) off the northwest coast of Australia.

“We concentrated the search in that area because the ‘pings’, the information we received, was the best information available at the time and that’s all you can do in circumstances like this, to follow the very best leads,” Truss said.

“We are still very confident that the resting place of the aircraft is in the southern (Indian) Ocean, and along the seventh ‘ping’ line,” he added, referring to an arc identified by analysis of satellite communications data from UK company Inmarsat Plc.

Flight MH370, carrying 239 passengers and crew, disappeared from radar screens on March 8 shortly after taking off from Kuala Lumpur bound for Beijing. 154 were Chinese nationals.

Passengers’ families have grown increasingly frustrated with the search and have complained that Malaysian authorities have not provided enough information.

Wen Wancheng, whose son was aboard flight MH370, said countries should release all the information they have about MH370’s flight.

“They have admitted that the ‘pings’ weren’t the original sound (from the plane), that they made it up. What really is the original data? They should show the whole progress of the flight to its end,” he said.

Malaysian Prime Minister Najib Razak is paying a six-day state visit to Beijing on which he is due to meet Chinese President Xi Jinping and Premier Li Keqiang.

Najib will not meet the families of missing passengers, about two-thirds of whom were Chinese.

A spokesman for Najib’s China delegation told Reuters on Wednesday he could not immediately comment on why there would be no meeting.

“We ask him to meet with us family members. My son, 154 passengers, the majority (of those onboard) were Chinese. In his country, they can’t be found. As a country’s prime minister, if you come to China, at very least you should meet with us family members,” Wen said.

Despite criticism from Chinese families, Malaysia has said it has repeatedly briefed next-of-kins and made great efforts to determine the plane’s fate.