New Caledonia's government has ordered people to stay home for at least 15 days from the end of Monday.
The French High Commissioner, Laurent Prévost, told a news conference the entirety of the territory's population will be ordered to stay at home for at least 15 days.
The new regulations ban public and private meetings and entail the closure of non-essential businesses.
Mr Prévost said only a small group of essential service personnel will be allowed to continue working.
People will only be allowed to leave their homes to buy food or go to medical appointments.
Four people are confirmed to have the virus in New Caledonia.
The president, Thierry Santa, said one of the new cases was a local pharmacist who has not travelled, raising fears of community transmission.
Watch Mr Santa and Mr Prévost's announcement on Sunday afternoon (in French):