It comes after the Government announced it was introducing new travel restrictions on people coming to New Zealand from Iran as a "sensible precaution". New Zealand citizens and residents will be allowed to return home, but will have to self-isolate for 14 days.

"This means people will not be able to travel from Iran to New Zealand and anyone who has been in Iran in the last 14 days will need to self-isolate," said Health Minister David Clark.

"The situation in Iran is obviously concerning. There is ongoing spread of the disease there, and a large degree of uncertainty about the scale of the outbreak and the ability to contain it."

The restrictions, which come into force immediately, will last initially until Tuesday. They will be reviewed every 48 hours, similarly to travel restrictions on people coming from or through China.

The Government has also decided not to allow any exemptions to let overseas students from China into the country. Health staff will also be made available for all international flights coming into New Zealand.

There have been no confirmed cases in New Zealand so far. However, two Kiwis have been tested positive for the illness on a cruise ship docked off Japan. They are currently being treated in a Japanese hospital.

More than 80,000 are infected with the illness worldwide, with about 2000 having died. Cases of the virus are recorded in about 48 countries.

The WHO was first informed of cases of the virus in Wuhan on December 31. It was identified as a coronavirus on January 7 and can spread through human-to-human transmission. There is little known about it but has revived fears of the SARS outbreak in 2002-2003 which killed almost 800 people.

"Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death," the WHO says.

"Standard recommendations to prevent infection spread include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms of respiratory illness such as coughing and sneezing."

There is currently no vaccine for the sickness, which is believed to have come from a marketplace in Wuhan. The Chinese city has become a ghost town with thousands of people there contracting the disease and many dying from it.