Malaysian officials say China has released satellite images of a large object floating in the Indian Ocean southwest of Australia.

Malaysian Defense Minister Hishammuddin Hussein told reporters Saturday that a Chinese satellite had spotted an object 22.5 meters by by 13 meters in an area were officials are hoping to find the missing Malaysia Airlines plane that disappeared two weeks ago with 239 passengers and crew on board.

However, he said there is still no confirmation that debris detected in the area is from the missing plane, and he had no further information. He said China would release further details later.

Hishammuddin said his biggest concern is that if the debris is not found and identified, the search will have to go back to the two corridors in a "huge and massive area."

Earlier Saturday, Australia dispatched search planes for a third consecutive day to search for any wreckage. However, the crews returned, saying they had found nothing.

Australian Deputy Prime Minister Warren Truss told reporters the search will continue until officials determine that further efforts would be futile.

Hishammuddin asked the U.S. Defense Department Friday for underwater surveillance equipment to help with the search.

A Pentagon spokesman did not say what equipment the U.S. might provide, but that Secretary of Defense Chuck Hagel is considering the request and whether it would be helpful in looking for the aircraft.

The Malaysia Airlines jet disappeared two weeks ago during a flight from Kuala Lumpur to Beijing. There has been no firm evidence so far of what happened to the jet.

Investigators are not ruling out anything, including catastrophic mechanical failure, terrorism or pilot suicide. They say it is possible that someone with knowledge of planes diverted it far off course.

Twenty-six nations have been hunting for the plane across an area covering more than 7 million square kilometers, from Kazakhstan to the southern Indian Ocean.