The cyclone which formed in Tuvaluan waters got as strong as a category three system - also affecting Fiji and Tonga.
The director of Tuvalu's disaster management office, Sumeo Silu, said based on initial reports about half of the country's population had been severely affected by the cyclone.
Food security was a major concern given ocean waves, whipped up by the storm, inundated gardens and strong winds uprooted trees and damaged banana and breadfruit trees, he said.