Pacific countries have continued to introduce sweeping measures to try and offset the coronavirus.
Nauru has declared a national emergency, suspending all flights apart from a single fortnightly service to Brisbane.
All arrivals will be required to spend 14 days in transitional accommodation before being allowed into the community.
"Nauru is particularly vulnerable to the threat of the coronavirus. The global impact indicates that should this virus enter Nauru, the results could be devastating," the government said in a statement.
"Our first and foremost objective is to protect our people."
Vanuatu's prime minister, Charlot Salwai, in an address to the nation on Tuesday night, announced the temporary suspension of all seasonal worker schemes in Australia and New Zealand.
The commissioner of labour said those already booked to participate can travel, and special measures will be introduced for those returning.
Mr Salwai also extended a ban on cruise ships for another 30 days, and promised a reduction in international flights, although he gave few details.
He also promised serious steps for kava bars, night clubs, pubs and other public gathering places, while other places like business houses, churches and schools would be required to adopt vigorous cleaning routines.
The president of New Caledonia, Thierry Santa, last night said all flights to the territory will be suspended.
In a news conference, Mr Santa said the measure would apply from early next week, although "a minimum link with the mainland [France] will be maintained, in particular for health reasons," he said.
All passengers arriving in New Caledonia must now also self-isolate for 14-days, and violators will face a penalty of 750 euros (NZ$1380; US$823).
In Tonga, tougher measures were also introduced on Tuesday night, with people from countries with community transmission of Covid-19 now required to spend 14-days self-isolated in a country with fewer than 60 cases - a measure that affects Australia, which has recorded more than 350 cases and five deaths.
However the restriction does not apply to Tongan citizens, permanent residents or their immediate family members.
Meanwhile, a quarantine site has been set up at the Taliai Army Camp in Fua'amotu, with three people already being held there.
All cruise ships and yachts are now barred from Tonga indefinitely.