Mike Kirsch, Al Jazeera's correspondent in the capital Port-au-Prince, said the president was under pressure to address the concerns of Haitians.
"Preval has his hands full - the situation here is not totally under control, even with the removal today of the prime minister," he said.
Also on Saturday, a UN peacekeeper was killed in the Haitian capital.
Sophie Boutaud de la Combe, UN mission spokeswoman, said the soldier was shot dead but that UN troops did not exchange fire.
Preval said that international aid money would be used to subsidise the price of rice and that the private sector had agreed to reduce the cost of each bag by $3.
He did not say when the emergency rice price reduction would go into effect.
He said he would appeal to Venezuela for help, particularly for providing fertiliser for Haitian farmers.
Hundreds of protesters and UN peacekeepers clashed over rising food prices and a lack of employment earlier this week.
Major-General Carlos Alberto Dos Santos Cruz, the UN commander in Haiti, said that a package of social, economic and political changes are needed in Haiti to provide immediate stability to the country.
"It is important for the people to have a peaceful life in Haiti," Santos Cruz said.
Global food prices have risen by 40 per cent since mid-2007. Most Haitians live on less than $2 a day.