Rebuilding has started on islands in Fiji affected by last week's volcanic eruptions in neighbouring Tonga and the tsunami that followed.

Fijian disaster management experts, military and civil servants today began assessment and repair works on six islands in the Lau Group, which are closer to Tonga than the main islands of Viti Levu and Vanua Levu.

A separate team of experts and military will join the Australian Defence Force's deployment to Tonga to aid in the relief efforts there.

Minister for Rural, Maritime Development and Disaster Management Inia Seruiratu said two Fiji government teams would leave Suva today to assess and repair damage in Ono I Lau, Vatoa, Moce, Moala, Vanuabalavu and Lakeba. The deployment is funded by the Australian government.

In a full cabinet briefing to the media, the government revealed an elderly woman died from fatigue while returning to the village she had fled during the tsunami.

There was substantial damage to schools, infrastructure as well as to fishing boats in the islands, some of which are closer to Tonga than to mainland Fiji.

"We are targeting six islands that we consider as more affected than others. It does not mean that we will leave all the rest but we prioritize our efforts when it comes to assessment, and of course, to relief work as well," Seruiratu said.

The deployment consists of two 20-member-teams with one covering Ono-i-Lau, Vatoa and Moce and the other Moala, Vanuabalavu and Lakeba.

"We have some limited information on the extent of the damages on the islands and that is why the teams are being sent out to verify the information that we already have."

The cost of the deployment was about $FJD 210,000 with a six-day-schedule, one day per island for each of the teams and three days sailing time, Seruiratu said.

Fiji health authorities are also warning the public that the risk of air pollution in parts of the country is high following the volcanic eruption in Tonga.

Fiji's Health Secretary Dr James Fong said the country's skies have been covered with dark clouds since last weekend.

"And for us to deal with that we have to make sure that all those at risk of respiratory disease - we have to have a list of the vulnerable people in the communities where the volcanic ash has gone over," James Fong said.

Fijians who suffer from asthma and other heart and lung infections are urged to remain cautious and ensure they have enough medication.

Assistance to Tonga

Meanwhile, a second team of 50 army engineers have been Covid-19 tested and are currently in quarantine pending Tongan government approval that they be part of the ADF's Tonga mission which depart Brisband on Friday 21 January.

Republic of Fiji Military Forces Commander Jone Kalouniwai said the Fijian government had made the offer to Tonga via Canberra and suggested the arrangements be similar to that which was used for the mission to the Solomon Islands following the unrest in Honiara in November last year.

"If that consent is given and with the availability of the HMS Adelaide are scheduled to depart Australia on Friday 21st January for Tonga. The plan is that the RFMF contingent will be airlifted within the next 48 hours to Australia to join the HMS Adelaide in Brisbane before it sails on to Tonga on Friday," Kalouniwai said.

RFMF standby personnel had undergone a PCR Covid-19 test and had been placed under strict isolation conditions until departure.

The acting Fijian Prime Minister Aiyaz Sayed-Khaiyum said he had spoken to Tongan Prime Minister Siaosi Sovaleni to express solidarity.

"Many of our people have friends and family in Tonga and we know we are all anxious for the latest news as the Pacific sisters and brothers whether what's been called a one in 1000 year event," he said.

Sayed-Khaiyum said he spoke via satellite phone with the Tongan leader on Sunday and has since formally assured him of Fiji's support working closely with the Australian and New Zealand governments to co-ordinate a regional relief effort.