More than 100 Australians and Canadians are still unaccounted for in Vanuatu six days after Cyclone Pam hit.
The category five storm flattened the Pacific island state last Friday, killing at least 11 people and leaving thousands homeless.
The Australian High Commission has made contact with hundreds of citizens since the cyclone, but many are still missing.
Some have managed to make brief contact over staticky satellite phones, and the Department of Foreign Affairs (DFAT) has chartered a helicopter to track them down and verify the calls.
The helicopter is also being used to track down Canadian citizens because, under an agreement, the Australian government provides consular services to them in Vanuatu.
DFAT is currently focused on locating any Australian citizens on the southern islands of Tanna and Aneityum, as well as Ambae and Pentecost islands in the north.
The RAAF has also ended free flights to Australia for shell-shocked expats and holiday-makers.
Air Vanuatu has also been swamped with requests for refunds by Australian tourists.
The company has told DFAT that many seem to be taking advantage of the disaster by trying to refund the cost of their return flights after they were flown out for free by the air force.
DFAT said an Australian volunteer and two British nationals were being flown into Port Vila from Pentecost island on Thursday.
The Australian had been based on the island when the cyclone hit.
Australian navy ship HMAS Tobruk is on its way to Vanuatu with 335 personnel onboard, as well as a Navy MRH90 Taipan helicopter and extra aid supplies.
Preparations are also underway to deploy two Army S-70 Blackhawk helicopters, Defence Minister Kevin Andrews said in a statement.