Visiting US President Barack Obama (R) shakes hands with Malaysian Prime Minister Najib Tun Razak in Putrajaya, Malaysia, on April 27, 2014. Obama started his three-day official visit to Malaysia on Saturday. [Photo/Xinhua]

KUALA LUMPUR/PERTH, Australia - US President Barack Obama said on Sunday that the United States was fully committed to providing more assets to assist in the search for missing Malaysia Airlines Flight MH370 in the southern Indian Ocean.

"I can tell you the United States is absolutely committed to providing whatever resources and assets that we can," Obama told a news conference in Kuala Lumpur with Malaysian Prime Minister Najib Razak.

A US Navy submersible drone scanned a remote patch of the Indian Ocean seabed on Sunday in its so far fruitless efforts to find signs of the missing plane, but bad weather prevented an air and sea surface search.

More than seven weeks after the jet carrying 239 people disappeared enroute from Kuala Lumpur to Beijing, and six weeks since the search moved from Asia to the Indian Ocean, authorities are now regrouping to decide how to proceed.

"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 in charge of the search told Reuters in an email.

Malaysia, China, Japan, New Zealand, South Korea, Britain and the United States are assisting Australia in trying to solve the most expensive search in aviation history.

"Obviously we don't know all the details but we do know if in fact the plane went down in the ocean on this part of this world, there is a big place and it is very challenging effort and laboriously effort," Obama said. "It is going to take quite some time."

A US defence official told Reuters on Friday that the sea search is likely to drag on for years as it enters the much more difficult phase of scouring broader areas of the ocean near where the plane is believed to have crashed.

Australia and Malaysia are under pressure to bring closure to the grieving families of those on board MH370, which disappeared on March 8, by finding wreckage to determine what happened to the aircraft.

Malaysia is also under growing pressure to improve its disclosure about its investigation, although Obama said on Sunday that US authorities had found it to be "fully forthcoming" in sharing information. Najib has said his government would make public a preliminary report into the plane's disappearance next week.

Last week Malaysian Transport Minister Hishammuddin Hussein told reporters that authorities would be "increasing the assets that are available for deep-sea search" and that his government was seeking help from state oil company Petronas which has expertise in deep-sea exploration.

The empty expanse of water some 1,000 miles northwest of Western Australia's state capital Perth is one of the most remote places in the world and also one of the deepest.

Until now, the undersea search has been focused on a 10 square km (6.2 square mile) circular zone where a series of "pings" detected earlier this month led authorities to believe the plane's black box flight recorders may be located.

The undersea search is set to be extended beyond this small area if the US Bluefin-21 drone fails to find anything, the search authority said on Saturday.