Many Haitians remained hungry and thirsty a week after the quake in Haiti's capital as the strained one-runway airport and chaotic seaport in the Caribbean country continue stalling the influx of aid cargoes.

The quake toppled most government buildings and shattered its ruling system. The Haitian government has been largely invisible since the quake and none so far is in effective charge in the shattered capital.

The U.S. military took control of the damaged airport with consent from the Haitian government. However, the United States has been criticized for turning away two World Food Program (WFP) planes and one French cargo plane over the weekend.

The Pentagon said Tuesday it would begin using other runways inside Haiti and across the border in the Dominican Republic.

An airport near Jacmel, to the southwest of Port-au-Prince, will hopefully be put into use within the next 24 hours, said Major General Daniel Allyn, deputy commander of the U.S. task force for relief efforts in Haiti.

Another airport that will be used is San Isidro in the Dominican Republic, Allyn said.

Thousands of Haiti's quake victims were struggling on Tuesday to board buses to the countryside in hopes of finding food on farms.

Up to 1 million people may flee the Port-au-Prince area for the countryside, straining Haiti's already precarious farms, said Laurent Thomas, director of the UN Food and Agricultural Organization's emergency operations.

The United Nations should play a leading role in the rescue and relief operations in Haiti, Chinese UN Permanent Representative Zhang Yesui, who holds the rotating Security Council Presidency for January, said in New York on Tuesday.

Zhang made the remarks after the 15-nation council unanimously endorsed a proposal by UN Secretary-General Ban Ki-moon to send 3,500 more peacekeepers to quake-hit Haiti.

"The rescue and relief operation in Haiti is facing great challenges at the moment," said Zhang.

The United Nations should act in a proactive way to tackle all the challenges including security, aid distribution and reconstruction, Zhang said.

A special representative of UN chief Ban Ki-moon Tuesday assured the world that situation in Haiti was "stable and normal."

"It is true that some incidents have happened of looting," said Edmond Mullet in a video teleconference from the Haitian capital.

"Food has been taken from destroyed supermarkets and shops, which is almost a normal situation in this kind of circumstances. But we have not seen, at all, any kind of violent rampages or swarms of looters, or people attacking or aggressive actions against anybody," he said.

The acting special representative said that in the last 48 hours military and police patrols in Port-au-Prince had been increased, with the number of Haiti National Police doubling Tuesday from Monday's 2,000 on patrol.

"We are helping with humanitarian deliveries," he added. "Little by little, day by day, we have been improving in our performance and working better."

The UN suffered great losses in the quake, with 46 of its staff members confirmed dead and more than 500 still missing.

Chief of the UN Mission in Haiti Hedi Annabi, his deputy Luiz Carlos da Costa, and Acting Police Commissioner Doug Coates of the Royal Canadian Mounted Police were among the UN officials who lost their lives.