The eye of the storm passed west of Haiti the night of Oct. 24. But its rain-heavy outer bands soaked the southern coast and capital for much of that week, causing many rivers to overflow. Authorities say the storm destroyed 70 percent of the crops in Haiti's south and caused widespread deaths of livestock.
Officials say that as many as 54 people died. The United Nations said that 1.6 million people were affected.
The office of prime minister Laurent Lamothe announced the appeal on Sunday.
The Caribbean country is still struggling to recover from a devastating earthquake nearly two years ago.