Prime Minister Jacinda Ardern has dismissed speculation on social media that the Government is poised to announce a nationwide lockdown to combat coronavirus.

"We will share with you the most up-to-date information daily. You can trust us as a source of that information," she told reporters in Rotorua.

"Do feel free to visit covid19.govt.nz - otherwise dismiss anything else. We will continue to be your single source of truth.

"Everything else you see, a grain of salt."

She said that misinformation only fuelled public panic.

"When you see those messages, remember that unless you hear it from us, it is not the truth.

"New Zealanders must prepare, but do not panic."

Ardern, who confirmed that she flew to Rotorua today on an Airforce plane, emphasised the importance of social distancing and the need to take it "really seriously".

She also stressed the importance of self-isolation, not only for those now arriving into New Zealand, but for people who have arrived in the past fortnight.

"The message I send is very clear. We take the health of everyone in New Zealand very seriously."

She would not be drawn on whether a state of emergency might be declared.

"Part of moving early is making sure everyone is prepared, prepared if you need to work from home, prepared if you need to cancel social events ... I need New Zealand to prepare for that."

She said she was keeping in contact with the Pacific nations, and if things changed, the travel restrictions needed to be broadened.

If the Pacific nations banned travel, New Zealand would support that decision, she said.

The Ministry of Foreign Affairs and Trade had advised her that New Zealanders overseas needed to decide whether to stay or come home, and to check flight availability.

Ardern said a process was in place around Covid-19 in schools, including shutting and cleaning when there were cases, but that plan could change depending on how widespread the outbreak was.

"What we've been basing everything we've been doing is around the public health advice around the ability to do contact tracing."

The Government wanted New Zealand to continue to be a place where all necessary contact tracing could still happen, and that would help slow the spread of the outbreak.

"There is a reason we have put an end of those mass gatherings. It's because of how difficult it is to maintain social distancing."

Although 80 per cent of the population will be fine if they have Covid-19, they could still transmit the disease to others who might not survive the disease.

Ardern and Finance Minister Grant Robertson are in Rotorua today to meet local authorities and representatives across the tourism, hospitality and forestry sectors, after the Government's $12.1b economic rescue package announced on Tuesday.

This morning the Government revealed a $600 million package to waive fees for six months that airlines usually have to pay, such as to Customs and the Civil Aviation Authority.

Any fee rises or pricing reviews from government agencies that charge fees at the border will be put on hold for 12 months. These agencies include the Ministry for Primary Industries, Civil Aviation Authority, Aviation Security Service and Customs.

This comes as Qantas and Jetstar announced they would suspend all international flights from the end of the month.

All public Anzac Day services in New Zealand have also been cancelled, following the cancellation of joint Anzac Day events in Gallipoli earlier in the week.

The Government has already banned public gatherings of people with more than 500 people, and further restrictions are expected to be announced this afternoon.

There are 20 confirmed cases in New Zealand, though that number is expected to rise.

Worldwide the number of cases has reached more than 212,000 people, with at least 8700 deaths.

London faces a lockdown and all UK schools have been ordered to close in coming days while US President Donald Trump and Canadian Prime Minister Justin Trudeau closed their 8850km US-Canada border to all nonessential travel.

On Wednesday, Italy saw a record new high in the numbers of infections and deaths reported, adding more than 4200 new cases for a total of 35,713 infections. Another 475 people died, bringing Italy's death toll to 2978.