Australians are being asked to help communities in Samoa, Indonesia, the Philippines, Vietnam and Cambodia.

In the last week, tsunamis, earthquakes, floods and two typhoons have struck the region, killing hundreds and leaving billions of dollars' worth of damage.

The Red Cross hopes to raise $5million worldwide for Sumatra and the United Nations' children's agency, UNICEF, wants to raise $250,000 in Australia for disaster relief.

UNICEF spokesman Martin Thomas said there were no credible estimates for the cost of rebuilding in Samoa but damage could be in the hundreds of millions.

''In terms of overall repair cost these were villages which were in some areas virtually wiped from the face of the earth. The devastation is almost total in those areas,'' he said.

Red Cross Australia's general manager of international operations, Donna McSkimming, said the cost to the region was immense.

''The estimates in the Philippines alone are about $6billion just to rebuild,'' she said. ''The [total cost] is estimated at $104billion Australian, which is extraordinary.''

In Vietnam, where Typhoon Ketsana wiped out crops and killed 99 people, local governments say they need $40million and 600 tonnes of rice seed, 20 tonnes of vegetable seed and 30 tonnes of maize seed.

For more, pick up a copy of today's Canberra Times