Jean-Max Bellerive told an emergency meeting of ministers in Montreal, including US Secretary of State Hillary Clinton, that the "colossal" effort would take "at least five to 10 years".
He said: "The people of Haiti will need more and more and more in order to complete the reconstruction. What we're looking for is a long-term commitment. Haiti needs the massive support of its partners in the international community in the medium and long term.
Responding to criticism that the Haitian government had been almost invisible during relief efforts he said it was working in "precarious conditions".
"We are fully conscious that the prime responsibility for our future lies in the hands of the Haitian government and the Haitian people."
Canadian Prime Minister Stephen Harper said: "It was not an exaggeration to say that at least 10 years of hard work awaits the world in Haiti."