Navy ships offshore, along with water purification machines flown in from Hawai'i by the Air Force, will generate water U.S. troops will fly and truck in to the storm survivors, Navy Adm. Timothy Keating said.

"Bangladesh needs help and we're happy to provide it," the head of the U.S. Pacific Command told reporters after a visit to the country to assess disaster aid needs. "We're going to try to restore fresh water to the southern part of Bangladesh."

The U.S. military is also prepared to offer medical care and to deliver food donated by international agencies, Keating said.

But fresh water is among the greatest needs in storm-hit areas.

Residents, who live in an area with low rainfall, rely on ponds to accumulate water for all their needs but these were flooded by the cyclone.

"When the tidal surge came in, it polluted or salinated all those ponds," Keating said. "So they have no drinking water, no water for bathing or washing dishes. Nor do they have water for their livelihood."

The USS Kearsarge, an amphibious assault ship, is already off the coast of Bangladesh. Another ship, the USS Tarawa, is en route. They will use the water purification plants they have on board to generate water.

An Air Force C-17 cargo plane from Hickam Air Force Base, meanwhile, has flown water purification equipment to Thailand. The machines will be delivered from there to Bangladesh.

The equipment, called reverse osmosis water purification units, can turn any water source — including salt water — into drinking water.

Keating anticipates many people with medical needs will be those who survived the storm but have yet to have bad wounds treated. There's a danger that the salt water brought in by the storm has infected some of those wounds.

The seriously wounded may be flown to the Kearsarge, which has six operating rooms, X-ray facilities, a blood bank and other equipment.

Keating didn't know how long U.S. troops would be aiding Bangladesh. That's to be decided by Bangladesh officials and the U.S. Embassy in Dhaka, but he said he hoped it would be a matter of days not weeks.