The secretary general of Tonga Red Cross Society says Cyclone Ian has exhausted the main stockpile of relief supplies in the capital, Nuku'alofa.
The category five storm, which killed one person and injured 14 others over the weekend, has displaced more than half of the 8,000-strong population in the country's northern Ha'apai islands and wiped out most of the food crops.
Sione Taumoefolau says all of the society's emergency supplies have been sent up to Ha'apai, leaving nothing in the warehouse on the main island of Tongatapu.
"It's cyclone season at the moment so I'm looking forward to appeal for any donor to replenish my stock. Otherwise if any emergency come through in Nuku'alofa, it is where about 75 percent of the population are, and it will be not good/ safe for us to do the responding."
Sione Taumoefolau says people will receive relief supplies of food after they have dug up tapioca and cassava crops flooded with sea water.
