New Zealand's deputy high commissioner in Niue, Tony Fautua, said most of the 1,300 islanders were bunkered down in their homes waiting for the storm to hit.

"It's Monday morning here and supposed to be the first day for opening for government offices and many businesses after the New Year holidays, but given the situation, everyone is going to be staying home and keeping safe," he said.

Fautua said the experience of Cyclone Ofa in 1990, which led to a state of emergency on Niue but no loss of life, had made local people more confident about facing Heta.

"There have been some more recent cyclones, but Ofa was an experience nobody had had before, and it has made them more resilient and able to adjust."

New Zealand MetService forecaster Liz McLaughlin said Tonga was reporting gale force winds but that Heta was moving more towards Niue where a hurricane warning was in force.

"It has deepened a little bit since yesterday and winds close to the centre are now estimated to be about 215kph with momentary gusts to 300kph," she said.

McLaughlin described Heta as one of the most intense cyclones in the region for some time, although there were indications it could start to weaken in the next 24 hours.

"But it is a very gradual process and that's too late for Niue."

States of emergency were declared in Samoa and American Samoa although the hurricane warnings were lifted as Heta swept south.

Many of the Samoan islands remained without power Monday and several roads were impassable, either cut by streams or blocked by rocks which had been ripped out of sea walls and tossed inland by raging surf.

There were reports one person had been swept out to sea on the Samoan island of Upolu but officials said there had been no deaths reported.

Although the hurricane warning has been lifted, air and sea travel between Samoa and American Samoa remained cancelled with services not expected to be restored until Tuesday.

At Pago Pago International Airport in American Samoa, part of the roof was ripped off the terminal building, the Samoa Air hangar was ripped apart, and nearly all the airport shops were damaged.

Dozens of people had to be evacuated from flooded coastal areas as waves up to eight metres high crashed ashore, swamping houses.

The Samoa Broadcasting Corporation reported extensive damage to houses with many losing their rooves and some hit by falling trees and coconut and banana plantations were flattened.

TERRA.WIRE