"If necessary, of the entire probable impact zone which is roughly 700 km by 80 km," Xinhua quoted Abbott as saying at a press conference after US submarine drone Bluefin-21 completed a sea floor search of a focused area in the Indian Ocean and found no contacts of interest.
The focused area was defined as a circle of 10 km radius around the spot where the second suspicious signal of aircraft black boxes was heard April 8.
Abbott said the new phase of search would be focused on the seabed of the expanded area, which would involve commercial contractors specialised in deep ocean search and may take six to eight months if weather conditions permit.
Contractual equipments could be deployed in weeks and the Bluefin-21 would continue its mission in adjacent areas, he added.
Acknowledging that it is possible to never find the ill-fated plane, Abbott vowed to continue the search as thoroughly as "humanly possible".
Malaysia Airlines flight MH370 vanished mysteriously about an hour after taking off for Beijing from Kuala Lumpur, shortly after midnight on March 8.
The Boeing 777-200ER was scheduled to land in Beijing the same morning. The 227 passengers on board included five Indians, 154 Chinese and 38 Malaysians.