Mr Clinton pledged to try and improve the way aid is co-ordinated
Haiti faces a massive task helping those who lost homes and livelihoods in the recent earthquake, former US President Bill Clinton has admitted.
Named by the UN as international aid co-ordinator, Mr Clinton was visiting Haiti's damaged capital Port-au-Prince.
There were protests as he met Haiti's president, after which Mr Clinton vowed to speed up sluggish aid deliveries.
Mr Clinton visited as 10 US citizens facing child abduction charges were denied conditional release.
The five men and five women, all Baptist missionaries, were sent back to jail with no further hearing scheduled for several days at least.
They deny allegations they tried to smuggle 33 children across the border to the Dominican Republic.
Tents and trucks
At least one million people currently need aid in Haiti after the magnitude 7.0 earthquake that officials say killed 212,000.
Visiting Port-au-Prince, Mr Clinton apologised for the delay in delivering and co-ordinating relief efforts.
"I'm sorry it's taken this long but these people are working hard and what I'm trying to do now is to identify the things that aren't being done and need to be speeded up and fill those blanks. I'm doing the best I can," he said.
According to the UN, many people are living near the rubble of their homes and some half a million are packed into some 315 makeshift camps which have sprung up around the city.
Mr Clinton said a supply of several thousand new tents would arrive in the next few days to help some of those still sleeping on the streets, along with a hundred lorries to help distribute more aid.
He said he would be looking at the structure of the aid operation to see how it could be made to function in a more effective way.
"Part of it is just shipping the volume of food in here that is necessary," he said, adding that there was also a considerable distance between the 16 main food distribution centres in the country.
On Friday, a crowd of Haitians took several tonnes of food and water from a lorry near the capital's airport and, in a separate incident, eight lorry-loads of food and water were raided in a nearby in an industrial park.
Mr Clinton said that both the Haitian authorities and the international community based in the country had suffered significant losses, hampering them in their attempts to co-ordinate international relief.
"All the ministers, thank God, survived, but they lost a lot of their family members and they lost a lot their senior aides," he said of the Haitian government, adding that the UN had faced its largest loss of life in the organisation's history.
"So the structure that would respond to this ordinarily was terribly damaged," he said.
He said he hoped that the capital that would emerge from the ruins of the city might be improved, with a better health service.
Earlier on Friday Haiti's prime minister warned that the case of 10 US missionaries charged with child abduction was a "distraction" from earthquake recovery.
The 10 have been charged with child abduction and criminal conspiracy.
When stopped on the border last Friday, the group said they were taking the children to an orphanage. But it has since emerged some of the youngsters' parents were still alive.
Mr Clinton said his mission did not involve working on behalf of the detained Americans.
"That's not within my mandate. I know that the State Department and government have had these discussions," he said.