"We are still in a very difficult situation," Bellerive told the Reuters news agency on Tuesday. "We still don't have a clear vision of certain problems - how we are going to relocate all those people."

It could take three or four years to return Haiti to its pre-quake state and up to 10 years to rebuild 250,000 houses destroyed by the quake, he added.

Aid pledge

Meanwhile at an emergency meeting of the Union of South American Nations (Unasur) in the Ecuadorean capital Quito, leaders pledged $300m in aid for Haiti.

Haiti in numbers
  230,000 men, women and children killed by the earthquake
  1,000,000 people estimated to still be homeless
  2,400,000,000 dollars pledged in aid
  10 years need to rebuild the capital Port-au-Prince
More numbers at: Truthout.org
The summit said members agreed to create a $100m fund to help road building, farming, health and sanitary projects that Rene Preval, Haiti's president, said were the highest priorities in his quake-ravaged country.

The 12 Unasur members also said they would also request a long-term, low-interest $200m loan for Haiti from the InterAmerican Development Bank, that Unasur would "underwrite and guarantee".

At the suggestion of Alan Garcia, Peru's president, Unasur said it would back efforts to keep all humanitarian assistance in Haiti "under the leadership" of the Haitian government.

The summit also stressed that international players in Haiti should conduct themselves with "absolute respect for [Haitian] national sovereignty and the principle of non-intervention in internal affairs".

Planning and restoring

Praveen Pardeshi, the senior co-ordinator of regional support for the UN's International Strategy for Disaster Reduction, said it was essential that efforts to rebuild were led by local officials.

In video


Al Jazeera's Rob Reynolds reports on the mixed reaction in Haiti to US military presence
Also read his blog here.

"The key issue here is to restore and support the national government to take ownership of both the planning and restoring of basic services like sanitation," he told Al Jazeera from Geneva.

"It is absolutely essential to strengthen the capacity of the national government, of the municipal authoritites, to take leadership in the long-term planning and applying better building codes."

In Port-au-Prince, a badly damaged supermarket collapsed on Tuesday trapping several people inside.

Rescuers used heavy-duty equipment to cut through tangled steel and concrete overnight but after nearly six hours of work there were no signs of life.

The collapse occurred as a private contractor was recovering the bodies of those killed in the January 12 quake.

Meir Vaknin, the site supervisor, said many of those buried on Tuesday were looters.

"I  was trying to get rid of them and when the building fell," he said.