New Zealand Prime Minister Jacinda Ardern has said she is self-isolating after coming into close contact with a person infected with coronavirus.

The exposure came on a flight from the town of Kerikeri to the largest city of Auckland.

New Zealand’s governor-general Dame Cindy Kiro was also on the flight on January 22 and has also gone into isolation.

Both women had been in the Northland region to do some filming ahead of New Zealand’s national day, Waitangi Day, on February 6.

“The Prime Minister is asymptomatic and is feeling well,” her office said in a statement.

“In line with Ministry of Health advice she will be tested immediately tomorrow and will isolate until Tuesday.”

Ms Ardern had been planning to get married this weekend but the celebration was postponed earlier in the week with the introduction of new Covid-19 restrictions.

Health officials listed a dozen flights as exposure events late on Saturday, a possible indication that one or more of the flight crew was infected.

Officials said genome sequencing would be completed on Sunday and was expected to show the infected person had the Omicron variant.

New Zealand has contained the virus for much of the pandemic, and has reported just 52 deaths among its population of five million, but an outbreak of the Omicron variant is starting to take hold and is expected to rapidly grow over the coming weeks.

About 77% of New Zealanders are fully vaccinated, according to Our World in Data. That figure rises to 93% of those aged 12 and over, according to New Zealand officials.