Obed Moses Tallis made the declaration this morning in Port Vila.
Earlier in the week the Council of Minister's had agreed to the declaration saying it was necessary to allow the government to mobilise resources and access funds to properly prepare the country.
There are no confirmed cases of Covid-19 in Vanuatu, but the island of Aneitum in the country's south was in lockdown after a tourist from a cruise ship which visited the island, tested positive for the coronavirus.
Blood samples from a number of locals on the island have been sent to New Caledonia for testing.
More details about what the state of emergency will mean will become clearer in the next day or so.
Solomons police caught up in Vanuatu Covid-19 scare
Officers on board the Solomon Islands patrol boat Auki have been caught up in Vanuatu's Aneityum Covid-19 scare.
During Vanuatu's election this month the crew of Auki assisted the Electoral Commission by transporting ballot boxes and personnel between southern islands in the country.
The Auki had just returned to the Vanuatu capital Port Vila on 21 March when news broke that a tourist on a cruise ship that had visited the same islands they had just been on had tested positive for Covid-19.
The Solomon Islands patrol was now anchored off Port Vila awaiting test results of about nine locals that had been sent to New Caledonia.
The Director of the Solomons Maritime Police, Chief Superintendent Fox Sau, said if any of the test results came back positive, the patrol boat and crew would have to be tested and quarantined in Vanuatu for 14 days.
"At this stage we cannot confirm when the RSIPV Auki will arrive back in Honiara."