A nightly curfew will apply until January 15 in a bid to contain the spread of the virus, Radio New Zealand International reported.
Residents of neighbouring East New Britain are being urged not to travel to West New Britain, neither by road nor by sea.
Two Covid-19 positive cases have been detected at the weekend, with one of them a man who had travelled from West New Britain before Christmas.
The other case is a mine worker in New Ireland province who tested positive at the Lihir Medical Centre.
PNG has to date recorded 799 Covid-19 cases and nine fatalities.
PNG Air began restricting flights into Hoskins with effect from January 1 to January 15.
For further information regarding passenger movement and bookings, contact the PNG Air call centre on 7411 2644,
"PNG Air apologises for any inconvenience this may cause and appreciate your understanding," PNG Air said in a news release.
