Australia 'Very Confident' Signals are from Missing Jet

Australian Prime Minister Tony Abbott said Friday he is "very confident" that signals detected in the search for Flight MH370 are from the aircraft's black box, whose batteries are waning fast more than a month after the plane vanished.

"We have very much narrowed down the search area and we are very confident the signals are from the black box," Abbott said, while warning that the transmissions were "starting to fade."

Abbott was speaking in Shanghai before meeting Chinese President Xi Jinping at the Great Hall of the People in Beijing, state news agency Xinhua said.

Two-thirds of the 239 on board the Malaysia Airlines jet were Chinese.

Xi later thanked Abbott for Australia's efforts to search for the missing Malaysia Airlines flight, and Abbott expressed appreciation for China's involvement, Xinhua reported.

Four signals linked to aircraft beacons have been detected by the Australian vessel Ocean Shield using U.S. equipment, with the first two analyzed as being consistent with those from aircraft flight recorders.

The beacons on the plane's flight data and cockpit voice recorders have a normal battery lifespan of around 30 days. The plane vanished March 8.

The Australian-led search for the Boeing 777, which disappeared en route from Kuala Lumpur to Beijing, is racing to gather as many signals as possible to determine an exact resting place before a submersible is sent down to find wreckage.

"We are confident that we know the position of the black box flight recorder to within some kilometers," Abbott said.

But he warned much remained to be done in "recovering wreckage from almost 4.5 kilometers beneath the sea, or finally determining all that happened on that flight."

The cause of the plane's diversion remains unknown.

The Ocean Shield is dragging a U.S. Navy "towed pinger locator" to listen for emissions from black boxes.

Striking a more cautious note than his prime minister, search chief Angus Houston said "there has been no major breakthrough in the search for MH370."

He said the Ocean Shield would continue to trawl for pings.

"It is vital to glean as much information as possible while the batteries on the underwater locator beacons may still be active," said Houston, head of the Perth-based Joint Agency Coordination Center (JACC) that is organizing the challenging search.

A decision to deploy a submersible sonar device "could be some days away," he said.

The JACC said the steadily dwindling search area had been further reduced Friday to two zones totaling 46,700 square kilometers (18,000 square miles), about 2,300 kilometers northwest of Perth.

No floating debris from the plane has yet been found, the JACC said, despite three weeks of searching in the area by ships and planes from several countries.

Houston has stressed the need to find the wreckage to be absolutely certain of the plane's fate, and has repeatedly warned against unduly inflating hopes for the sake of victims' relatives, whose month-long nightmare has been punctuated by false leads.

Frustrated Chinese relatives have accused the Malaysian flag carrier and authorities of bungling the response to the plane's disappearance and withholding information, which Malaysia's government denies.

The rancor has strained ties between Malaysia and China, whose government also has put pressure on authorities in Kuala Lumpur.

Malaysia's environment minister told Agence France Presse on Friday that China has postponed plans to send a pair of pandas to Malaysia next week.

China had agreed in 2010 to lend the two giant pandas for 10 years in Beijing's latest use of "panda diplomacy" to cement ties with other countries.

"They (China) are waiting for the results of MH370," environment minister G. Palanivel said in a text message.

"They will delay the arrival," he added, saying the animals may be sent next month.

The pandas were to arrive April 16 on a Malaysia Airlines flight, which would have caused embarrassment for Beijing.

The JACC has said the next step in the search, once the pinger locator had done all it could to narrow the area, would be to send down a U.S.-made autonomous underwater vehicle called a Bluefin-21 to investigate.

But officials have warned the submersible would be operating at the very limits of its capability given the vast depths involved.