Governments around the world have been urged to honour their financial pledges to the countries worst-hit by the Indian Ocean tsunami.
The efforts are now focused on reconstruction
The Asian Development Bank said there was a shortfall of more than $4bn (£2.1bn) promised for rebuilding India, Indonesia, the Maldives and Sri Lanka.
ADB president Haruhiko Kuroda said the world's attention must stay focused as work moved into reconstruction stage.
Nearly 300,000 people died in the 26 December earthquake and sea surges.
Many thousands more had their homes and livelihoods wrecked.
The ADB delivered its latest post-tsunami report at an international meeting of donor countries, regional governments and aid agencies in the Philippines capital, Manila.
In his opening speech, Mr Kuroda issued a reminder of the dreadful impact of the waves which pummelled the Asian coast:
Mr Kuroda said aid agencies and governments needed to improve their co-ordination and spend the money in a predictable, transparent, strategic and effective manner.
- in India, 700km (430 miles) of road were damaged
- in Indonesia's Aceh province 44% of people lost their livelihoods.
- in Sri Lanka, 100,000 homes were lost and 65% of the fishing fleet damaged.
"Given the scale of the recovery, even with our best efforts at co-ordination, the potential for gaps, overlaps and duplications is significant," he warned, saying tools needed to be developed to avoid this.
He called on the countries receiving aid to fight corruption and make sure that the money was spent wisely.
His concerns were echoed in recorded messages from former US Presidents Bill Clinton and George Bush Senior.
"They [governments] know that the international community is concerned about the use of funds," said Mr Bush, who toured tsunami-hit countries with his successor in February.
"And they told us they intend to be good stewards of the money raised for their aid," he said.
The Sri Lankan Foreign Minister, Lakshman Kadirgamar, has told the BBC that his country has not yet received any of the money promised by governments - although people all over the world had been generous in their contributions.