Cyclone Winston has turned back towards Tonga's northern islands and has intensified into a category four storm.
The Fiji Met Service said Winston is currently around 250 kilometres north-northwest of Niue and 340KM east-southest of Tonga's Niuatoputapu.
Met director Ravind Kumar said the Tonga's northern islands, particularly Vava'u, can expect to be hit for a second time by the storm on Friday.
Mr Kumar said the storm could strengthen further into a category five storm.
"It is slow-moving and now trekking westward. We estimate that the average winds are up to 165 kilometres per hour with momentary gusts up to 230 kilometres an hour. We expect these winds to increase to 185 kilometres an hour in the next 18 to 24 hours."
Meanwhile Disaster Management authorities in Tonga are currently meeting while local police report at least 63 families in Vava'u and 35 families in Ha'apai are already in shelters.
A gale warning remains in force for Niue with gusts of up to 90 kilometres an hour.