The Vanuatu Ministry of Health has confirmed two cases of dengue have been detected by the National Disease Surveillance system.
Both cases were in Port Vila and were being managed at the victims' homes.
The Ministry of Health had sent blood samples to New Zealand for further testing.
It had also reconvened its Dengue Early Warning Committee to address the issue.
The Director of the Health Ministry, George Taleo, said his staff would strengthen surveillance around the country to ensure detection of suspected dengue cases.
He said at the same time they would be alert to the threat posed by similar mosquito borne diseases that were now prevalent in the Pacific like Zika and Chikungunya.