The underwater search for any trace of the plane's wreckage hasn't found a clue.
The jet with 239 people aboard went missing on March 8 during its flight from Kuala Lumpur to Beijing.
The search has been going on in the Indian Ocean floor with a US Navy submersible drone.
"We went all in on this small area and didn't find anything. Now you've got to go back to the big area," the official told Reuters.
Underwater search area for MH370 to widen
As the 13th-day of the underwater search for the missing Malaysia Airline flight MH370 begins Friday, the hunt is all set to widen as the sonar scan of the depths of the Indian Ocean nears completion.
The autonomous underwater vehicle (AUV) Bluefin-21 has so far searched 95% of a 310 sq km area, 10 km in radius and 4.5 km deep off the west Australian coast around the second towed pinger locator detection from April 8, without yielding a single result, Xinhua reported.
Up to eight planes and 10 ships are assisting in Friday's search. "If no contacts of interest are made, Bluefin 21 will continue to examine the areas adjacent to the 10 km radius. We are currently consulting very closely with our international partners on the best way to continue the search into the future," the Joint Agency Coordination Centre (JACC) said Friday.
Malaysia Airlines flight MH370 vanished mysteriously about an hour after taking off for Beijing from Kuala Lumpur shortly after midnight 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.
(With PTI inputs)