The hundreds of thousands of people whose homes were destroyed had settled in more than 200 open spaces around the city. The lucky ones managed to secure tents for their families, but most have to make do living under the tropical sun on blankets, plastic sheets or under tarpaulins strung between tree limbs.

Ban's announcement came as search-and-rescue teams packed their dogs and gear Thursday, with hopes almost gone of finding any more survivors in the ruins. The focus has now shifted to keeping the injured alive, fending off epidemics and getting help to the hundreds of homeless.

"We're so hungry," said Felicie Colin, 77, lying outside the ruins of her Port-au-Prince nursing home with dozens of other elderly residents who have eaten very little since the earthquake hit.

Four ships managed to dock at the capital's earthquake-damaged port, holding out the promise of a new avenue for getting aid to the city. A Danish navy ship was seen unloading crates. But the going was slow, since only one truck at a time could maneuver on the crack-ridden pier.

The picture was especially grim at emergency medical centers, where shortages of surgeons, nurses, tools and supplies have backed up critical cases.

Food was reaching tens of thousands, but the need was much greater. Perhaps no one was more desperate than the 80 or so residents of the damaged Municipal Nursing Home, in a slum near the shell of Port-au-Prince's devastated cathedral. The quake killed six of the elderly, three others have since died of hunger and exhaustion, and several more were barely clinging to life.

At least 124 people were saved by search-and-rescue teams that worked tirelessly soon after the quake, the European Commission said. But as hopes faded Thursday, so long after untold numbers were trapped in the debris, some of the 1,700 specialists, working in four-dozen teams with 160 dogs, began demobilizing.

On Thursday, 18 hospitals and emergency field hospitals were working in Port-au-Prince. But the burden was overwhelming: Some quake victims have waited for a week for treatment, and patients were dying of severe infections from untreated wounds, according to Greg Elder, deputy operations manager for Doctors Without Borders.

The Pan American Health Organization said hospitals need more orthopedic surgeons and nurses, more supplies, better sanitation and water.

Doctors said patients were dying from untreated wounds and they warned of potential outbreaks of diarrhea, respiratory-tract infections and other communicable diseases in the hundreds of makeshift camps. A team of epidemiologists was on its way to assess that situation, the Pan American Health Organization said.

"A large number of those coming here are having to have amputations, since their wounds are so infected," said Brynjulf Ystgaard, a Norwegian surgeon at a Red Cross field hospital.

Almost $1 billion in foreign aid has been pledged to help Haiti recover from the quake, and the White House said the US share has climbed to about $170 million.

The UN World Food Program said it has delivered at least 1 million rations to about 200,000 people, with each ration providing the equivalent of three meals daily.