He was also expected to meet Ecuadorean troops with the UN peacekeeping mission in Haiti during his visit.
The BBC's Huw Williams in Port-au-Prince says a new relief programme is under way, with the United Nations paying Haitians to help clear rubble from the streets.
A UN spokesman said thousands of local people were being paid up to $20 (£14) a day under the Cash for Work programme, giving them a guaranteed wage for the foreseeable future, our correspondent reports.
Earlier, the acting head of the UN mission in Haiti, Edmond Mulet, told the BBC that reconstruction would take several decades and that all of Haiti's recent development had been undone.
He said the logistics of the relief effort were a nightmare, with Haiti's inadequate infrastructure destroyed and a shortage of vehicles.
Reconstruction was not starting at zero, but "below zero", Mr Mulet said.
Haiti's president on rebuilding
The UN has estimated that 75% of the capital, Port-au-Prince, will have to be rebuilt. Salvage crews have begun to clear the rubble.
Meanwhile, Mr Mulet said, areas around Port-au-Prince are being prepared for the creation of tented settlements for the homeless currently living in makeshift camps.
He said 200,000 heavy-duty tents had been ordered to cope with Haiti's rainy season, which typically begins in May, and its hurricane season, which is expected to start around June.
Haitian President Rene Preval earlier this week called for the urgent airdrop of 200,000 more tents and 26 million ready-to-eat meals before the rainy season begins.
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