The top United Nations humanitarian official on Wednesday issued a plea from Haiti for more medical assistance to help the country fight a cholera outbreak.

UN undersecretary-general for humanitarian affairs Valerie Amos, left, and International Organization for Migration camp management officer Ludovic Lataste visit an internally displaced persons camp in the Tabarre neighborhood of Port-au-Prince on Tuesday. (Allison Shelley/Reuters)More than 1,400 people have died in Haiti from the disease, and as many as 20,000 are sick.

"We think that the rate of infection will rise, but we can deal with this," Valerie Amos, the UN's undersecretary-general for humanitarian affairs, told CBC News. "Cholera is treatable."

Amos is currently in Haiti's capital, Port-au-Prince, for a two-day visit.

"We need more treatment centres," she said. "We need more doctors and nurses, and I will be calling on our partners — not just other governments but also NGO partners [and] UN agencies — to make sure that we get more resources.

"We desperately need more supplies as well.

Clean water and sanitation facilities are among the supplies most urgently needed, Amos said.

Earlier this week, Nigel Fisher, the Canadian who is heading up the UN's humanitarian efforts in Haiti, said bureaucracy and indecision on the part of Haitian officials is slowing down the aid response to the outbreak.

He said local governments need to act faster to approve cholera treatment centres and that designated burial sites for cholera victims must also be set up.

Amos concurred.

"We need decisions by government," she said. "We need land to be given over which can be used for the burial of people, but we also need land so that we can build some of our treatment centres. This is absolutely critical.

"We are working with local authorities, because people are fearful sometimes about a treatment centre being put up in their area, because they think it's bringing cholera."