At least one person has died and more than 30 remain missing after a ferry sank off the coast of Vanuatu, the prime minister's office has confirmed.

The MV Matui, an inter-island ferry carrying more than 40 passengers and crew, set sail on Friday from the island of Santo bound for Ambae in very rough seas but never arrived. The vessel sank in bad weather amid strong winds.

Fifteen of those on board have been accounted for alive, and one body has been recovered, according to a statement posted by Prime Minister Jotham Napat's office. More than 30 people remain missing at sea.

"Our hearts and prayers are with the families who have lost loved ones," the statement read. "Search and rescue operations are continuing."

"To the survivors, we pray for your strength and recovery. To the families of those missing and those we have lost, please know that the nation stands with you in this time of grief."

The government said search efforts in open waters were being scaled back, with operations shifting toward the south-east coast, where currents may have carried survivors. Matai Seremaiah, the member of parliament for Luganville who is assisting in the search, confirmed that efforts would concentrate on that stretch of coastline.

The Maritime Rescue Coordination Centre in New Caledonia said it was assisting with the search. A French Armed Forces aircraft was deployed on Sunday morning, and the centre reported that 12 people were located during that morning's operations.

The government said the sinking "appears to be the result of strong winds and marine warnings not being heeded, and possibly of negligence including overloading of the vessel." A full investigation has been launched to establish the facts and prevent a recurrence.

Vanuatu police, the country's Maritime Safety Authority, and the ferry's operator, Tui Shipping Agency, did not immediately respond to requests for comment.