The tropical storm which tore through Tonga overnight is expected to hit Fiji around 6pm.
Residents of Fiji's major islands are bracing for bad weather as Cyclone Gita swings north.
The Fiji Meteorological Service says the Category 4 storm made landfall over the remote southern island of Ono-i-lau overnight.
It has brought tidal surges and potentially destructive hurricane-force winds.
Forecaster Steven McKay says it'ssouth of Kadavu and Viti Levu, but it's tracking northeast. He says Kadavu, its surrounding islands and southern parts of Viti Levu, should be expecting strong to gale-force winds.
As the storm approached last night, communications were lost with isolated parts of the archipelago, leaving hundreds cut off from contact with the outside world.
Desperate people boarded up their homes and stocked up on essential supplies while praying and hoping for the best before heading to the safety of emergency shelters.
Residents in neighbouring Tonga were picking up the pieces yesterday after the cyclone left a trail of destruction overnight Monday, ripping off roofs, flattening homes and injuring dozens of people.
Winds were gusting nearly 200km/h as the fringes of the cyclone approached Fiji, cutting communications to some residents.
The cyclone was tracking south of the main Fijian islands but National Disaster Management Office director Anare Leweniqila was particularly concerned for the southern islands of Ono-i-Lau and Vatoa.
"Right now we have lost all communications."
Three villages on Ono-i-Lau and one on Vatoa are home to about 200 people.
Damage from Cyclone Gita on the islands of Tonga. Photo / Supplied
Wind gusts at Ono-i-Lau had reached 190km/h last night. The cyclone was still a category 4 but had potential to develop to category 5 as it continued to move west.
Forecasting models still predict the storm will track towards New Zealand, and may pass over the country early next week as an ex-tropical cyclone.
The Fiji Navy was on standby as Gita approached the country yesterday. Fijian Waisale Naga said winds were strengthening on the main island last night and the ocean swell was getting stronger.
"The sea is reasonably rough and that changed in the last hour or so."
Naga was in his "secure home" with three families from his neighbourhood.
His house was one of three evacuation centres in the area.
Fiji's Red Cross Society had mobilised teams as the country braced for impact.
Thirty emergency response trained volunteers from Viti Levu and 10 from Vanua Levu were on standby.
Back in Tonga, the island nation was picking up the pieces after Gita passed through on Monday night, wreaking havoc with its powerful winds and torrential rain.
The destruction of the cyclone left three people with serious injuries and 30 others with minor injuries in Tongatapu, Tongan Police spokeswoman Sia Adams said.
Fiji Red Cross prepare for Tropical Cylone Gita. Photo / Supplied
The cyclone also contributed to the death of a 72-year-old man who suffered a heart attack, according to the Tongan Director of Health. The man was rushed to hospital on Monday night, but died before arrival.
The winds which peaked at 230km/h flattened parts of Parliament House and levelled dozens of homes, churches and powerlines.
"I have never experienced anything like that," Tonga High School French teacher Virginie Dourlet said.
The roof of the Tongan Meteorological Building was ripped off, forcing updates to be deployed by radio.
Graham Kenna, from Tonga's National Emergency Management Office, said the damage was widespread and severe.
His Majesty's Armed Forces had been clearing debris from roads all morning to allow emergency services to get across the main island of Tongatapu to assess the damage.
New Zealand's Defence Force deployed one of its P-3K2 Orions yesterday afternoon to conduct an aerial survey of damage caused by the cyclone.
Kiwi Defence personnel also deployed 12 tonnes of aid supplies and a 10-member team to Tonga by air to assess the damage.
Members of the Samoan Red Cross visit people in their homes to assess the damage caused by Tropical Cyclone Gita. Photo / Supplied
Kenna said it was the worst situation he had ever been in.
