Watch: Relief supplies for Cyclone-ravaged Tonga prepped by busy NZ Defence personel

Emergency supplies from New Zealand are set to be sent to Tonga this afternoon in an effort to provide assistance to Cyclone hit Tonga.

Severe damage was caused by Tropical Cyclone Gita overnight, levelling houses and tearing off roofs as winds reached nearly 280km/h.

Follow 1 NEWS NOW's live updates as Cylone Gita heads towards Fiji

A RNZAF C130 Hercules aircraft carrying emergency supplies including hygiene kits, shelter kits, jerry cans and tarpaulins, along with a New Zealand government team will fly to Tonga this afternoon.

"The full extent of damage caused by Cyclone Gita is still being assessed but there is an immediate need for assistance on the ground," Foreign Affairs Minister Winston Peters says.

Cyclone Gita hit Tonga overnight leaving widespread destruction including flooding and power outages. Source: 1 NEWS

"Initial assessments indicate there has been extensive damage to homes in Nuku'alofa and some damage to commercial buildings," he says.

"About 5,700 people sought shelter in evacuation centres overnight, and it is expected these numbers will increase substantially tonight."

New Zealand is coordinating the international relief response alongside other countries including Australia.