Effective from midnight Sunday, all travellers, except for those coming from the Pacific islands, will have to self-isolate for 14 days on their arrival to New Zealand

The PM says the rules are the toughest in the world

She told New Zealanders not to travel overseas if they don't have to and issued stark advice: no hugs, hongi or handshakes

All cruise ships have been asked to not come to NZ until June 30

There will also be further announcements on mass gatherings

Prime Minister Jacinda Ardern has announced all travellers will have to self-isolate on their arrival to New Zealand, apart from those coming from the Pacific Islands.

She said the measures - in effect as of midnight Sunday - include New Zealanders.

The restrictions will be reviewed in 16 days and there will be more advice for self-isolation next week. There were already clear guidelines for employers on sick pay and working-from-home advice.

It will be the strictest border restriction rules in the world, Arden said.

"I make no apologies. This is an unprecedented time.

"If you don't need to travel overseas, then don't. Enjoy your own backyard for a time. Stop handshakes, hugs and hongi.

"We are a tough, resilient people. We have been here before.

"We are taking every step we can as a Government.

"Look after your family, look after your older ones."

All cruise ships are also being asked to not come to New Zealand until June 30. It does not apply for cargo ships.

Essential air freight will still be allowed to enter the country for things like pharmaceuticals.

There will also be further announcements on mass gatherings based on the criteria of: large events in close proximity, events that are non ticketed and events that have a large overseas number of people.

There was no decided number on how many people constituted a mass gathering but the overseas criteria of 500-1000 was similar to what the government was considering.

"We understand these decisions are disappointing people but we have to prioritise people's health," Ardern said.

Up until today, travel restrictions in New Zealand included preventing foreign nationals travelling from or transiting through mainland China or Iran from entering New Zealand.

Prime Minister Jacinda Ardern during her media conference in Christchurch on Friday. Photo: NZ Herald

People exempt from the temporary restrictions were self-isolating for 14 days after their return.

People who had been in Italy or the Republic of Korea (excluding airport transfer) were required to self-isolate for 14 days after their return.

And people who had travelled to Hong Kong, Japan, Singapore and Thailand (excluding airport transit) are being asked to aware of coronavirus symptoms but do not need to self-isolate if they are well.

The new travel restrictions will be a massive hit to Air New Zealand, 52% owned by the Government. Around 41% of the airline's $6 billion annual revenue comes from international flights.

While it dominates domestic flying, it has already scaled back some domestic routes because of falling demand from business travellers. On Monday it said it could no longer forecast its profit because of uncertainty over the future of air travel.

Its share price has plunged since the start of the year when the coronavirus became known and the company has lost nearly half of its market capitalisation.

Other airlines serving New Zealand will also move quickly to change their schedules.

Ardern said New Zealand was already registering all travellers who are self isolating once entering NZ the PM said. 10,500 people have already self isolated in NZ.

The PM says our pandemic which hits hard and fast must be dealt with by "flattening the curve" to have the rate of cases in the right place - either at home on in hospital if needed.

"We must go hard and fast."

A smaller number of cases have allowed New Zealand "to care for them in the right place," the PM said.

"We must plan and prepare for more cases."

She urged people there was no need for anyone to "take a run on their supermarket".

No one else in cabinet is self isolating besides Tracey Martin, she said.

The parliamentary speaker has been considering business continuity cases for self isolation of MPs and parliamentary staff.

The World Health Organisation has declared the coronavirus a pandemic as the number of confirmed cases globally reaches 145,000. Just over 5400 people have died. Almost 70,000 people have recovered.

It was announced today New Zealand now has its sixth positive case of the coronavirus, an Auckland man.

There also two probable cases of Covid-19 in New Zealand.