US officials helping in efforts to locate a missing Malaysian plane today said they are shifting their search to the Indian Ocean region amid reports that the aircraft could have flown for several hours before it disappeared nearly a week ago.

"It's my understanding that based on some new information that's not necessarily conclusive -- but new information - an additional search area may be opened in the Indian Ocean," White House spokesman Jay Carney said.

"And we are consulting with international partners about the appropriate assets to deploy," he said without specifying the nature of the new information.

The move to expand the search to the Indian Ocean came after the US' defence and aviation experts said that there was a significant probability of the plane to be at the bottom of the Indian Ocean.