"Let's dry our eyes to rebuild Haiti," Preval said at a ceremony held on a flower-decked platform at the University of Notre Dame's nursing school in the capital.
"Haitian people who are suffering, the courage and strength you showed in this misfortune are the sign that Haiti cannot perish. It is a sign that Haiti will not perish," said Preval.
The ceremony marked a brief pause in the government's recovery effort from Haiti's worst natural disaster.
Al Jazeera's Rob Reynolds reporting from Port-au-Prince, said: "Today is really a chance for Haitians to come together and offer one another's support - or at least begin with coming to terms with the unimaginable suffering that has engulfed the country since that day one month ago."
While aid workers from foreign governments and private organisations rushed to feed the disaster's survivors and homeless in the days immediately after the quake struck, the destitute still suffer and Haiti is now concerned about how to feed its people in the medium and long-term.
Minister Joanas Gue, Haiti's agriculture minister, voiced his country's concerns at the keynote speeck on Friday at the UN World Food Program headquarters in Rome.
"I want to find a tent before the rain starts, to shelter my children. The rain will bring diseases and I don't want them to get sick"
Edmonde Roseline, mother-of-four
Poor nutrition was common in Haiti even beforehand, when three-quarters of Haitians were living on $2 a day.
Al Jazeera's Jonah Hull spoke to a mother-of-four, Edmonde Roseline, as she strove to provide the bare necessities for her children.
"As long as the children can eat and drink, that's enough for me," she said.
"When I am here with them I just try to stop them getting sad."
The country's approaching rainy season is making the agricultural situation even more urgent - while bringing danger for families like Edmonde's.
"I want to find a tent before the rain starts, to shelter my children," she told Al Jazeera.
"The rain will bring diseases and I don't want them to get sick."
An estimated 50,000 families, or about 272,000 people, have received emergency materials to build their own shelters, according to the UN office that coordinates humanitarian affairs.