The cyclone hit the island's northernmost region on Feb. 12 and tracked down the east coast, inflicting widespread devastation.
On Sunday, police said two more people had died in hard-hit Hawke's Bay in circumstances related to the cyclone.
More fatalities are possible, New Zealand Prime Minister Chris Hipkins told reporters in the capital Wellington, as 6,431 people remained missing, while 3,216 had been reported safe.
Lives had been "turned upside down" by the disaster and recovery was a "steep mountain ahead," he said, pointing to disrupted telecommunications, shortages of fresh water and damaged roads still restricting access to some areas.
Supply chains were disrupted causing problems moving goods, many crops had been destroyed, and 28,000 homes were still without power, he said.
A team from Fiji would leave for New Zealand in the coming days to assist with recovery, one of 12 offers of international aid received so far, Hipkins said. Twenty-seven emergency workers from Australia are assisting with the relief effort.
Hipkins added that those found looting will be arrested.
Reuters