Two dead, two missing after heavy New Zealand flooding

The bodies of two men were found in floodwaters in two separate incidents in a northern suburb, police said.

The flooding also swept a man away in a community south of Auckland, and another person is unaccounted for after a landslide brought down a house in the city centre.

"My thoughts are with everyone in Auckland as they wake up this morning to survey the damage and as they face an uncertain day ahead," new Prime Minister Chris Hipkins said in a statement.

Police said they were "continuing to respond to a high number of calls to weather-related incidents".

The flash flooding turned many of Auckland's roads into rivers on Friday, and the wild weather closed the city's airport, which is the country's largest, with ankle-deep water in some terminals.

Airport authorities said there would be no flights in or out of the facility before mid-day Saturday.

Hipkins, who was sworn in Wednesday after Jacinda Ardern's shock resignation, wrote on Twitter that government agencies were "working flat out" to help.

His plans to visit the city were delayed because of the poor conditions, he said, adding: "I'm advised movement around Auckland remains difficult."

Hipkins said the national crisis management centre, housed under the parliament building in the capital Wellington, was helping to coordinate the emergency response.

The persistent downpour washed out Elton John's concert on Friday at Auckland's Mount Smart Stadium amid concerns for crowd safety.

Emergency services were swamped by calls for help as civil defence officials warned residents to stay home.

Auckland residents have been urged to only contact emergency services if facing "life-threatening" danger.

Auckland mayor Wayne Brown warned late Friday that the clean-up operation would be a "major, major job".