"There are two issues we have to focus on at this stage and over the next six months: providing people with shelter, however temporary, and giving them the opportunity to earn an income," she told a news conference.

"What would really make a difference would be if people could get back to work ... We must not create a dependence on aid, which would create a real problem in the longer term."

Up to 300,000 people in several countries and island states died in the December 26 tidal waves that followed an undersea quake off Aceh province on the northwestern tip of Indonesia -- the area worst hit in the disaster.

But many more in other coastal communities from Thailand to Sri Lanka, southern India, the Maldives, the Seychelles and Somalia in east Africa, lost their homes and jobs.

"We are talking about hundreds of thousands of people who will need support for at least the next six months, especially in Aceh," Wahlstrom said.

Last month the UN issued an appeal for $977 million in funding to support the relief effort over its first six months.

But donors' pledges cover less than half the money wanted for temporary housing and job creation, though other parts of the relief programme are fully covered, she said.

Income-generating programmes needing support include debris clearing, which could employ local people, and simple boats so that fishing -- a key occupation in the region -- can resume.