Japanese aid groups participating in the largest international disaster relief operation in Southern Asia said Tuesday that efforts to help the survivors are falling short despite the unprecedented level of support and donations.

"We have received a lot of public responses, probably because the disaster occurred during the yearend and New Year's holidays," said Kazuyoshi Misawa, a spokesman for Tokyo-based aid group Peace Winds Japan. "But the scale of damage is enormous and we still need to deliver more supplies."

Peace Winds is delivering medicine and food to Meulaboh, a town on the western coast of the Indonesian island of Sumatra that took the brunt of the tsunamis triggered by the Dec. 26 magnitude 9 temblor off the island.