Vanuatu was due to host the meeting of the region's leaders in August.
The Council of Ministers said the impacts and uncertainty surrounding Covid-19 and the aftermath of Cyclone Harold led to the decision.
Vanuatu will talk with Fiji, which is due to host next year's summit, about whether the Vanuatu meeting can be held in 2021.
The Vanuatu Daily Post reported the country was already scheduled to host a number of regional events in 2021, including the Pacific Community Leaders meeting.