Tonga is nervously waiting for a direct hit from Tropical Cyclone Gita - which is forecast to become a category 4 or 5 event.
New Zealand's Ministry of Foreign Affairs is advising against all tourist and non-essential travel to Tonga.
"There is a high risk to your safety in Tonga due to Tropical Cyclone Gita and we advise against all tourist and other non-essential travel,'' a statement said.
New Zealand aid agencies and groups are gearing up to help the people of Tonga, as the island nation prepares itself for a direct cyclone hit.
The Tongan police have imposed a curfew in the Nuku'alofa central business district from 9pm to 7am Tuesday. Only emergency situations could break the curfew.
Tropical Cyclone Gita is due to make landfall about 7pm (local time is the same as NZT). It has strengthened overnight and is forecast to strike Tonga.
A state of emergency has been declared in the island kingdom and it is thought the cyclone will be the strongest storm ever to hit Tonga in history.
New Zealander Richard Young, manager for the Sandy Beach Resort in Tonga, said although the resort was at a coastal location it was relatively safe as it was in the eye of the storm.
"We are not going to get hit too hard; we are not at risk, the main island is going to be hit hard."
The worst he was expecting was winds up to 90km/h which was a stark contrast to the 200km/h winds expected on the main island.
Despite the forecast he was still taking all safety measures to ensure he, and the resort was prepared.
"We moved all of our boats into safe locations, cleared the trees of coconuts, pulled shutters over exposed windows and any outdoor furniture is locked away.
"All of the guests have been given a briefing on what to do and when, and what to expect," Young said.
All guests but three had left the resort, he said.
If things went sour the resort had generators for backup power and Young had already contacted all necessary people as they were expecting to lose communication within the next few hours.
"The storm right now is passing south of us. We will be in the eye of it. What we have now will only increase slightly."
Another Kiwi in Tonga expects the nation's poorly constructed homes to be devastated by Cyclone Gita.
Joanna Burke said people were hunkering down as wind and rain picks up.G
Burke said the majority of Tongan houses were made of blocks, corrugated iron and wood, and didn't expect them to fare well in 200km/h an hour winds.
She says people seemed well-prepared, stocking up on essentials before power is shut off to the main island at 7pm.
NZ aid and development group Tearfund is already preparing emergency packs for families on the ground, preparing homes and equipping evacuation centres with supplies.
Tearfund head Ian McInnes said there was a real risk of homes and crops being completely destroyed.
"Communities on the main island of Tongatapu are low-lying - making them vulnerable to flooding from rain and sea surges,'' he said.
"If Gita makes landfall as a category five cyclone, we would expect houses to be destroyed along with damage to coastal roads and crops, meaning people would lose their livelihoods.''
McInnes said members of the group's partner association in Tonga - 'Ola Fou - had humanitarian specialists were also preparing to co-ordinate and implement an aid response if one is needed in the coming days.
People in Tonga are being urged to take heed of warnings and calls to be prepared - stocking up on food, water, first aid gear and other necessary supplies.
The messages follow an incident at a hardware store yesterday; which saw police officers shut down the Pacific Timber and Hardware branch in the capital city, Nuku'alofa, for opening on a Sunday.
By opening its doors, the store breached the country's Sabbatical laws.
Cyclone Gita's arrival comes as the country is already dealing with another situation; after declaring an outbreak of dengue fever just over a week ago.
The outbreak was declared following the death of 12-year-old New Zealand girl Toafei Telefoni, who died at a local hospital after contracting the disease while visiting the country.
Oxfam New Zealand is on standby to respond to the aftermath of Cyclone Gita; due to hit the country's most populated islands of 'Eua and Tongatapu.
"With the country already addressing an outbreak of dengue fever of Tongatapu, the deterioration of sanitation conditions on the island could increase the risk of a second disaster due to the spread of dengue and other vector and water-borne diseases,'' Oxfam said.
Oxfam's director of programmes in Tonga, Jane Foster, said the organisation had a long-established presence in Tonga and Samoa and therefore have solid pre-positioned emergency supplied already in-country ready to be deployed when required.
"Once the urgent needs are assessed, we are expecting to help co-ordinate the supply of clean water and sanitation for those affected by the disaster.''
The NZ High Commission in the country's capital, Nuku'alofa, was closed today and will be tomorrow, as staff have been remain indoors.
New Zealanders in Tonga requiring urgent consular assistance may contact the New Zealand High Commission in Tonga on the following number +676 23122 or after hours +676 8817022