Riots that flared on Monday have forced the United Nations to ground flights carrying soap, medical supplies and staff to Cap-Haitien and Port de Paix, cities in a northern region where the cholera fatality rate is highest.
The violence in Cap-Haitien saw protesters burn and loot 500 tonnes of food from a World Food Programme warehouse.
The insecurity, which restricted movement in Haiti's second city, also forced aid agency Oxfam to suspend a project to chlorinate water for 300,000 people, and the World Health Organisation to stop training medical staff, the U.N. Office for the Coordination of Humanitarian Affairs (OCHA) said in a statement.
Oxfam said its staff were on standby to resume operations as soon as possible. Demonstrators who have set up roadblocks are preventing people from getting to hospital for treatment, it added.
"Every day we lose means hospitals go without supplies, patients go untreated and people remain ignorant of the danger they are facing," said the U.N. humanitarian coordinator in Haiti, Nigel Fisher, in the statement released late on Tuesday.
"We call upon all involved in these clearly orchestrated demonstrations to stop immediately."
The appeal came as media reported the first case of cholera in neighbouring Dominican Republic. The victim was said to be a Haitian who had crossed the border after a trip home.
"We also expect to see cholera cases in the Dominican Republic," Jon Kim Andrus, deputy director of the Pan American Health Organisation (PAHO), told a press briefing in Washington on Tuesday.
"We expect to see cases continue to increase and we expect to see increased geographical spread."
'CLOSE TO BEING OVERWHELMED'
The United Nations on Tuesday blamed political and criminal "spoilers" in Haiti for attacks on U.N. peacekeepers, saying their intention was to sabotage Nov. 28 elections by manipulating public fear over the cholera epidemic.
"We call upon all who perpetrate such acts to remember that such supplies and the urgent work to combat cholera are the difference between life and death for everyone affected by this epidemic," Fisher added.
Anger towards the 12,000-strong U.N. peacekeeping mission in Haiti has focused on its Nepalese contingent, the subject of widespread rumours it may have carried the cholera bacteria to the Caribbean island nation, which had not experienced an epidemic of the diarrhoeal disease for a century.
The world body says the Nepalese peacekeepers have tested negative for the disease.
The latest number of deaths from the cholera epidemic is 1,039, with 16,799 hospitalised cases of the highly contagious disease, according to the Haitian health ministry.
The hindrances to aid work come at a time when medical charity Medecins Sans Frontieres (MSF) is warning that the outbreak is stretching it and other relief groups to the limit. It has called for other organisations to step in to help tackle water, hygiene, sanitation and medical issues.
"MSF is worried about the limited response to the epidemic," Stefano Zannini, MSF's head of mission in Haiti, told AlertNet. "More medical staff are arriving, but there's a chronic lack of personnel here in Haiti and we are close to being overwhelmed."