Aid agencies and governments are battling to get supplies to hundreds of thousands of stricken Haitians who are without medical help, food, water, blankets, and power.

There is chaos at the country's main airports as planes are having difficulty in landing, and supplies are being stacked up and stored.

U.S. Secretary of State Hillary Rodham Clinton flew to the capital Port-au-Prince on Saturday, to have urgent talks with Haiti President Rene Preval. The thrust of the meeting is to establish ways and means of getting the aid provided by the U.S. and other governments, as well as international humanitarian organizations, to those that need it.

Clinton said on Friday the authorities were, "racing against time."

"I don't know how much longer we can hold out," Dee Leahy, a lay missionary from St. Louis, Missouri, who was working with nuns handing out provisions from their small stockpile, told The Associated Press. "We need food, we need medical supplies, we need medicine, we need vitamins and we need painkillers. And we need it urgently."

Thirty one countries have already sent aid to Haiti. The U.S. Navy’s aircraft carrier USS Carl Vinson arrived off the coast of the country on Friday, and will deliver 600,000 daily rations to stricken Haitians.

Tens of thousands of people have been confirmed dead in the disaster, while tens of thousands more are missing, many of them buried under rubble.

Rescuers are frantically searching the ruins of the capital, and other parts of Haiti for survivors.

Bodies have begun to pile up and are being buried in mass graves.

"If the government still exists and the United Nations is around, I hope they can help us get the bodies out," Sherine Pierre, a 21-year-old communications student whose sister died when her house collapsed told AP.

The U.S. is sending a hospital ship, USNS Comfort (pictured), to the stricken Caribbean country.

Comfort will leave its home port in Baltimore early Saturday and is expected to arrive in Haiti Thursday, delivering medical and surgical services aboard one of the U.S.’s largest trauma facilities.

“This is a moment when we feel we can have a huge impact,” along with other military medical providers already on the ground, as well as those from nongovernmental organizations and the international community, the ship's captain, Navy Capt. James Ware, said Friday. “Our hope is to work with those individuals, side by side, to truly help the people of Haiti.”

The hulking hospital ship, three football fields long and one wide, has 250 hospital beds and a 550-person medical team that includes trauma surgeons, orthopedic surgeons, head and neck surgeons, eye surgeons and obstetricians and gynecologists.

The team will also include medical professionals from the Navy, Army, Air Force and U.S. Public Health Service, as well as nongovernmental organizations.

Ware said he expects his staff to initially see about 500 patients a day when it arrives in Haiti, working up to 750 or more, and to conduct 20 to 25 surgical procedures a day.