"Half a million people in Indonesia are still living in temporary shelter. Entire communities were destroyed," Food and Agriculture Organisationpost-tsunami operations coordinator Alex Jones said in a statement.

"Reconstruction takes a lot of time, not just money, and it can only go as fast as the local communities are willing and able to go."

But he said the international response to the catastrophe had been "exceptional" and the "overall message is a positive one".

FAO Director-General Jacques Diouf said the donor response was "huge" but aid was still not getting through to some people in need.

"What the world needs is a standby global disaster fund that would make immediate intervention possible," he said.

The mightiest earthquake in 40 years with a magnitude of 9.3 on the Richter scale unleashed waves up to 15 metres (49 feet) high that raced towards the shores of a dozen nations on December 26 last year.

Around 220,000 people were killed, almost two million left homeless and economic damage ran to billions of dollars.