More ships and aircraft carrying aid are due to arrive in Tonga in coming days as the international community responds to calls for urgent assistance from the Pacific island nation following a devastating volcanic eruption and tsunami.

The first flights from Australia and New Zealand landed in Tonga on Thursday with much-needed supplies of water for sanitation and hygiene as well as shelter, communication equipment and power generators.

A New Zealand maritime sustainment vessel carrying 250,000 liters of water and able to produce 70,000 liters per day through a desalination plant, the HMNZS Aotearoa, is expected to arrive in Tonga on Friday.