Australian Prime Minister Tony Abbot appealed Thursday to families of MH370 passengers to be more patient after more ships joined the extensive scouring of remote southern Indian Ocean waters to find the trace of missing plane.

Following a meeting with his Malaysian counterpart Najib Razak in RAAF Base Pearce near Perth, Abbot told the press that despite the constant refining of the search area and the remoteness of the spot, he was upbeat about unveiling the MH370 mystery as the best brains in the world are working on this.

"We are throwing everything we have at it and we are confident that we have, ourselves the technical capacity, or that we can obtain the technical capacity from our friends and allies to ensure that we get the best possible outcome," Abbot said.

The three-week massive hunt, labeled as "the most difficult search in human history" by the Australian prime minister, has turned out to be futile.

"I say to the family members of the people on that flight, please be patient. I know this is an extraordinarily difficult, indeed devastating, time for you, but we will not let you down," Abbot said.

Some eight planes and nine ships scoured an area of about 223, 000 square kilometers, 1680 kilometers northwest of Perth on Thursday.

British submarine HMS Tireless and HMS Echo already arrived in the southern Indian Ocean to assist in the multinational retrieval effort. Malaysian frigate KD Lekiu is departing HMAS Stirling on Thursday to provide surface sweep.

Time is running out to find any debris to work out a likely crash zone and recover the aircraft's black boxes before batteries pinging their location die.

"We do owe it to the families of the 239 people on board, we do owe it to our good friend Malaysia, we owe it to the people and the government of China, we owe it to the troubled citizens of a wider world to do everything to we can to solve this extraordinary mystery," said the Australian prime minister.

Malaysian airliner MH370 vanished from radar screens less than an hour into its flight from Kuala Lumpur to Beijing on March 8. Partial military radar tracking revealed it turning west and recrossing the Malay Peninsula, apparently under the control of a skilled pilot.

Hopes of a breakthrough had been raised after the Australian Maritime Safety Authority (AMSA) revealed last Friday a new search zone about 1,100 kilometers northeast of the previous one based on analysis that the plane had been travelling faster than previously thought.

After being briefed about the international search effort and had breakfast with the crew in RAAF Base Pearce, Najib expressed his gratitude to all people who have contributed to such a Herculean task.

"In a time of great tragedy for the countries with citizens on board and the families whose loved ones are missing, this cooperation has given us all heart."

Australia has set up a new Joint Agency Coordination Centre ( JACC) based in Perth to oversee day-to-day operations.

Seven countries, Australia, the U.S., China, New Zealand, Japan, South Korea and Malaysia, have contributed ships and aircraft to the search off the coast of Perth.

"The disappearance of MH370 is without precedent, so too is the search," Najib said.