UNICEF New Zealand says it is still waiting for the Tongan government to assess the damage of Cyclone Ian before it can move into the devastated islands of the Ha'apai group.
The Tongan government has not requested any formal international help.
The UNICEF programmes manager, Tanya St George, says it has offered its assistance to the government and has emergency supplies and personnel on standby.
Ms St George says its main concern is ensuring access to drinking water, food, shelter and sanitation, and helping displaced women and children.
But she says as communication is still limited in some affected areas, the full impact of the cyclone is still being assessed.
"Assessing the extent of the damage and the resources on hand and what's going to be needed takes time so that's why we need to wait for the government to make the call. We don't have a full picture yet of what their needs are."
The UNICEF New Zealand programmes manager, Tanya St George.