There has been just one new confirmed case of Covid-19 in New Zealand, and four new probable cases, the Health Ministry has revealed.

Prime Minister Jacinda Ardern and Director-General of Health Dr Ashley Bloomfield are giving a briefing on the Covid-19 coronavirus.

If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs) or call your GP

They are speaking just hours ahead of New Zealand's move to alert level 3, reducing restrictions on businesses and schooling.

The move from level 4 to level 3 takes place at 11.59pm tonight.

An app to help the country's contact tracing efforts is also in the works, with the Ministry of Health revealing today it would be ready within two weeks.

Yesterday, the Ministry of Health reported another nine cases - all linked to known infections - with no new deaths.