Peacekeepers have been handing out food and clothing aid
The head of the UN mission in Haiti has called for a new government to be chosen as soon as possible to avoid further unrest over food prices.
Hedi Annabi said the calm in Haiti was precarious and he urged all political groups to reach a stability pact.
Haiti's Senate sacked Prime Minister Jacques-Edouard Alexis on Saturday for failing to address problems.
The UN also announced it would hand out more than 7,000 tonnes of food, in the first place for children and mothers.
Riots this month over rising food and fuel prices have led to the deaths of at least six people, including a UN peacekeeper.
Haiti is one of the poorest countries in the world. Most Haitians earn no more than $2 a day, and they have struggled to feed themselves as the prices of rice, beans and fruit have risen by 50% in the last year.
UN spokeswoman Michele Montas said food provided by the World Food Program would be given as a priority to children, pregnant women and nursing mothers in the north, west and central regions of Haiti.
The UN children's fund Unicef would double its child feeding programme to combat malnutrition and increase spending on water and sanitation projects, she said in New York.
The Senate voted to ask President Rene Preval to appoint a new prime minister and cabinet.
Mr Preval has adopted an emergency plan to reduce the price of rice by more than 15% but people are calling for action to reduce the cost of other staples.
"Reducing the price of rice, even slightly, is a good thing, but how about the other essentials?" Melanie Preval, a 33-year-old mother of three, told Reuters news agency on Wednesday.
"We cannot just boil the rice and eat it."