Cyclone Jim has gathered strength, with winds of up to 208 kilometres an hour.
It's north of the main island of New Caledonia and the major hurricane is predicted to head south east.
Vanuatu officials are warning people about Cyclone Jim in the southern areas of Shefa and Tafea.
The Vanuatu Meteorological Service says vessels are strongly advised not to go out to sea until the system moves out of the area.
Flooding, including coastal flooding is expected over the central and southern islands of Vanuatu later today.
It says communities and individuals living near or along river banks, along coastal areas, on flat plains, or in areas prone to landslides are advised to seek safe shelter.