A year long deep sea search for the Malaysia Airlines plane missing in the Indian Ocean will start in September with a southern part of the search zone prioritised.
Australian Deputy Prime Minister Warren Truss said analysis of the airline's failed satellite phone call attempt to Flight M370 suggests the plane might have turned south earlier than previously expected.
The 1.1 million square kilometres search zone remains the same size but authorities have been able to make refinements with satellite data.
Australia and Malaysia will split the $52 (NZ$58m) million cost.
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Truss, who met with his Malaysian and Chinese counterparts in Canberra on Thursday, said they were cautiously optimistic the aircraft will be recovered.
Malaysian Transport Minister Liow Tiong Lai said the investigation had stalled.
"We need to find the plane, we need to find the black box to come to a conclusion," Lai told reporters in Canberra.
MH370 went missing on March 8 on the way from Kuala Lumpur to Beijing with 239 people on board, including six Australians and 153 Chinese nationals.
In the search area, the Australian Transport Safety Bureau contracted vessels Fugro Discovery and Fugro Equator, and the Malaysian contracted GO Phoenix, will tow vehicles with sonar equipment, multibeam echo sounders and video cameras.
They will also carry equipment to quickly recover the black box if the aircraft wreck is found.
Analysis of mapping data from the 87,000 square kilometres already searched has uncovered two underwater volcanoes and sea depths up to 1500 metres deeper than previously known.
Truss and Lai also discussed ongoing recovery efforts for MH17 - the Malaysia Airlines jet downed by a missile strike over eastern Ukraine on July 17, killing 298 people, including 38 Australians.