Some of the aid agencies operating in Asia after the tsunami disaster lack the skills needed, charity Oxfam says.
One month on, the region's inhabitants are still clearing debris
Exactly a month on, Oxfam praised the international response but the agency also highlighted problems with the quality of the aid that had been given.
Millions were affected by the disaster, in which more than 280,000 people are believed to have died.
A UN spokeswoman has told the BBC that two-thirds of the aid money pledged worldwide had already been delivered.
Of a "flash appeal" for $977m (£522m) requested by the UN for immediate emergency operations, $775m has been received, the UN's Office for Co-ordination of Humanitarian Affairs (OCHA) told the BBC News website.
In other developments:
- Indonesia says it is sending a top-level delegation to Finland for talks with the exiled leadership of Aceh's separatist rebels
- Schools are reopening in Aceh on Wednesday
- The US navy is surveying waters off Indonesia to determine how the tsunami altered the sea bed
- Firefighters are battling a blaze fanning across 3km of Banda Aceh
Oxfam pointed to difficulties co-ordinating the aid, saying that some inexperienced aid agencies were working in the disaster zone without the necessary skills and competence.
In particular, it criticised the way that some houses had been rebuilt in Sri Lanka, saying they were too close together, causing sanitation problems.
In its report "Learning the lessons of the tsunami: one month on", it said governments in the region should accredit international agencies and ensure their work was suited to their experience.
TSUNAMI DEATH TOLL
Indonesia: at least 95,000 dead; 133,000 missing, presumed dead
Sri Lanka: 31,000 dead; 5,637 missing
India (inc. Andaman and Nicobar islands): 10,744 dead; 5,640 missing
Thailand: 5,384 dead; 3,130 missing
Somalia: approx. 150 dead
Maldives: 82 dead; 26 missing
Malaysia: 68 dead
Burma: 59 dead (government figure)
Tanzania: 10 dead
Bangladesh: 2 dead
Kenya: 1 dead
Seychelles: 1 dead
"The amount of money raised means that governments and aid agencies must address issues of the quality, not just quantity of aid," said Oxfam Britain Director Barbara Stocking, quoted by AFP news agency, ahead of the report's publication.
Ms Stocking also said the victims of the tsunami "will never escape poverty" unless issues like Third World debt and trade were properly addressed.
Oxfam also expressed concerns that pledges of aid would not be lived up to.
However, the Red Cross said it was winding down its appeal after raising sufficient funds for its aid efforts.
More than 70 Red Cross societies around the world are involved in the campaign.
Details of how much money they raised are expected to be announced on Wednesday.
You can watch a BBC News Special "Asia One Month On" on BBC1 and BBC World at 1930GMT