The U.S. military on Wednesday expanded its contribution to the tsunami recovery effort in south Asia, with the Army sending helicopters and about 100 people from bases in South Korea (search) and the United States to fill a variety of medical and logistics needs.

The U.S. Army command in South Korea is sending several CH-47 (search) medium-lift helicopters to help distribute humanitarian supplies, and it may dispatch UH-60 choppers to operate as air ambulances, officials said.

The Army also is sending four mortuary affairs teams to help recover human remains and identify victims, as well as engineering support teams to assist in assessing damaged infrastructure and in planning reconstruction.

Also, the Army Special Operations Command (search) is sending three civil affairs teams to help coordinate relief and one psychological operations team to help broadcast relief information.

Navy Adm. Thomas Fargo, commander of the Hawaii-based U.S. Pacific Command, told a Pentagon news conference Tuesday that the military would roughly double the number of U.S. helicopters involved in the relief mission, to about 90. On Wednesday the Pentagon said 48 were already operating.

As of Wednesday, about 13,400 U.S. military personnel were involved in the relief effort, including 12,000 aboard ships and 1,000 in Thailand, where an air base is serving as the U.S. command center. There also are U.S. military personnel in Sri Lanka, Indonesia and Malaysia.

The Pentagon also said Wednesday that 28 cargo planes, including four C-17 and six C-5 heavy lift aircraft, were flying transport missions in the area, compared with 16 planes a day earlier.

The military said it had delivered more than 610,000 pounds (247,500 kilograms) of relief supplies -- water accounting for about half of that -- as of Wednesday.

In a separate news conference Tuesday, William Winkenwerder, the assistant secretary of defense for health affairs, said the military is prepared to send as many as eight portable hospitals, including a 25-bed version that could be flown aboard two C-17 cargo planes from Yokota air base in Japan.

The White House, meanwhile, said Tuesday that President George W. Bush ordered the Pentagon to provide $65 million of "defense articles and services" as disaster assistance to Indonesia, Thailand, Sri Lanka, India, Maldives, Malaysia, Burma, Kenya, Somalia, Tanzania, Bangladesh and the Seychelles.

Two 10-person teams of military and civilian forensics specialists have already been sent from the Joint POW/MIA Accounting Command in Hawaii to assist in recovering, sorting and identifying remains.

Winkenwerder said the Defense Department is coordinating with other government agencies and with the United Nations and World Health Organization to determine what additional medical assistance is needed. He cited the vulnerability to disease of the hundreds of thousands of displaced people in Indonesia and other countries hit by the earthquake and resulting tsunami on Dec. 26.

Fargo said helicopters, capable of flying from aboard ships or from land bases and able to operate around the clock from austere landing strips, are especially useful in relief operations.

"Helicopters are a tremendous advantage, because, of course, they don't have the same restrictions as fixed-wing aircraft in terms of how many you can have on the ground at a time," he said.

There are 17 helicopters aboard the aircraft carrier USS Abraham Lincoln, which is operating off the coast of Sumatra. Twenty-five more helicopters are aboard the USS Bonhomme Richard, an amphibious assault ship that began flight operations off Sumatra on Tuesday.