Cristobal Cristoff, a street vendor in this lakeside tourist resort in southern Guatemala, was unfazed by the natural disaster that covered dozens of nearby villages with mud last week. The calamity following Hurricane Stan left at least 652 people dead and another 577 missing nationwide, officials said.

On Tuesday morning, Cristoff set up a little sidewalk table and laid out drawings of Lake Atitlan and traditional Mayan cloths. There were no tourists to buy his wares, but he said he was hopeful they would return soon.

With the search for bodies halted in many areas and relief efforts underway following the destructive mudslides and floods, the government also began to turn its attention to reconstruction.

First, though, authorities had to cope with the heavy damage to many roads, which has made it difficult for army troops to deliver food, medicine and water donated by private aid groups.

The government issued an appeal to the United Nations for $21.5 million in aid, saying its own emergency funds could not meet the demands of the crisis, the Associated Press reported. Officials said that about 107,000 people were living in shelters and that the country would need about 22,000 tons of food over the next three months.

In the regions most affected, some highways have been destroyed and many bridges are too weak to hold cars, officials said. Rocks, uprooted trees and earth slid down mountains, crushing pavement and creating steep, dangerous cliffs. For several days, blocked roads prevented rescue workers from reaching some sites.

"We have been evacuating people on foot, and in vehicles when we can," said army Maj. Luis Barahona, who is helping to coordinate rescue efforts. "We've been carrying them food and water."

On the road leading to Panajachel, a large town near the hardest-hit villages in Guatemala's highlands, a mudslide shook the foundation of a crucial bridge, cutting off traffic. Now, both provisions and people must enter on foot.

Catalina Aqueno, 48, said she walked five miles to Panajachel from her home in Santa Catarina Palopo. From there, she walked another mile up the mountain, crossed a bridge on foot and hitchhiked a final mile to the provincial capital, Solola, where stores were still selling food and water.

"I want to cry," Aqueno said after finishing her exhausting trek. "The bridge is on its last leg."

In Solola, she bought gas for her stove and drinking water. She said she was trying to reopen a small restaurant in her home, but all she had to cook was beans.

In the morning, a dozen soldiers began shoveling mud off the bridge. They said they would reinforce it with metal supports so buses could start running again.

In southern Guatemala, officials said, the Nahualate Bridge was destroyed when large chunks of broken asphalt in muddy rainwater smashed into its foundations. The bridge is a crucial point in the major artery connecting southern coastal states with the rest of the country.

President Oscar Berger has said reconstruction of the country's infrastructure is a priority. He has planned for days to visit victims of the disaster but inclement weather prevented helicopter landings. On Tuesday, he was finally able to fly to Santiago Atitlan, a major town in the highlands near several destroyed villages, and said he had come to "share the pain" of survivors who had lost loved ones, according to the Associated Press.

Without swift repairs to the country's arteries, much of the country is at risk of a food shortage, Eduardo Secaira, the country's international aid coordinator, told CNN on Tuesday.

"The problem is that the south coast is also in bad shape, so basic crops like corn and rice are gone," he said. The government will have to ensure that food is shipped to affected areas, he said.

Gen. Bantz J. Craddock, commander of the U.S. Southern Command, pledged on Monday to lend engineering and technical support to help restore bridges and highways. The United States is also lending Guatemala a dozen Black Hawk helicopters to ship food and supplies to remote villages.

"We are committed to providing help and search-and-rescue efforts for those affected using our equipment and people," Craddock said at a news conference here.

The United States has already delivered 5,000 blankets, 15,000 gallons of drinking water and 11,000 gallons of fuel to victims, officials said.

Until the roads are repaired, soldiers have been walking with bags of corn and bottles of water to stranded villages where people do not want to leave their homes. Bill Muirhead, an American who moved to Panajachel from Chicago 15 months ago, said getting food to villages around the lake has required Herculean efforts. "I bought some corn and beans in Solola and we walked back and forth, carrying the 100-pound bags of food on our backs," Muirhead said.

View from a U.S. Army helicopter shows destruction from a mudslide, one of many near the town of Panajachel. At least 652 are dead and 577 missing in Hurricane Stan's aftermath in Guatemala.