By Gavin Stamp
BBC News business reporter
A year after the Asian tsunami, governments have yet to deliver $550m (£315m) of the humanitarian aid pledged for the victims.
British charities have spent £128m on tsunami aid this year
That amounts to about 9% of the $6.7bn total pledged, according to figures from the United Nations, which co-ordinated the relief effort.
The UN data excludes support for long-term reconstruction, meaning that significant contributions from countries such as Australia are not recognised.
Taking into account long-term reconstruction funding, companies, individuals and governments pledged a total of $13.6bn.
The UN figures show that the US has given just 38% of the aid it pledged.
In Europe, the UK, France and Italy, as well as the European Commission, have also failed to fulfil their pledges so far.
According to the UN figures, the Commission still has to pay about $70m while the UK has $12m outstanding.
The UK says it has given £195m towards humanitarian assistance and long-term reconstruction, £55m of this through the European Union.
Among Asian countries, China and Australia are among those yet to pay up while Germany only paid its full $128m sum in late December.
There are also concerns about a shortfall in money for long term reconstruction in the worst affected countries.
Despite this, the financial response to the tsunami, which killed 200,000 people in December 2004, has broken all records.
The disaster prompted an unprecedented personal response, with individuals and firms giving $4bn towards the relief effort, amounting to 67% of all the humanitarian aid.
Children's agency Unicef received almost twice as much as it had sought in donations, while the World Health Organisation and the World Food Programme secured 95% of targeted funding.
In the UK alone, leading charities raised more than £420m under the auspices of the Disaster Emergency Committee.
Indonesia, which suffered the highest death toll of all affected countries, has been the largest recipient of aid.
It secured financial pledges of $4.4bn, $750m of which has been spent.
At a governmental level, Japan has been the largest single donor to date, contributing $500m to the humanitarian effort.
More to come?
The US said it spent $185m on emergency assistance in the aftermath of the disaster, although UN figures suggest that an additional $217m also pledged has yet to be handed over.
Aid officials admit they have doubts about whether some major donors, including the US, will fully deliver on their promises.
Many Sri Lankans are still living in temporary housing
"There are certainly substantial uncommitted humanitarian pledges out there," a UN official involved with the tsunami relief effort told the BBC.
"We hope that the agencies and the donors will nail these down because they are needed."
"In the majority of cases, there is still the hope and expectation that (the donors) will follow through."
Some countries have ring-fenced funding for rebuilding infrastructure and economic livelihoods destroyed by the disaster.
The US Congress approved $900m in long-term financial support for affected countries.
About $630m of this has been allocated to a recovery and reconstruction fund, of which 90% has been earmarked for dispersal.
According to the US Agency for International Development, such assistance is badly needed.
The cost of reconstruction in India, Indonesia, the Maldives and Sri Lanka - the four worst affected countries - has been estimated at more than $10bn.
Only $7.7bn has been secured against this total and former US President Bill Clinton, the UN's Special Envoy, has warned of worrying gaps.
The Maldives is facing a projected shortfall of $122m for its long-term recovery at a time when a decline in tourism and soaring oil prices has further weakened its economy.