Prime Minister Jacinda Ardern has slammed "irresponsible" reporting on the arrival of the coronavirus COVID-19 in New Zealand.

New Zealand's first case was confirmed on Friday afternoon in a 60-year-old person who arrived on a flight from Iran and Bali on Tuesday. They remain the only confirmed case of the virus in New Zealand.

COVID-19 has infected more than 83,000 people worldwide, and killed nearly 3000.

Ardern on Saturday said New Zealand's response so far has been "textbook".

"My message to the general public - in my view, some of the headlines we've seen have been irresponsible. Some of those headlines have caused unnecessary anxiety for the public," she said.