Security and defence will underpin talks between Australia, New Zealand and Pacific nations as China flexes its muscle in the region.
Deputy Prime Minister and Defence Minister Richard Marles will on Monday travel to Tonga for the defence ministers' meeting.
He will then head to Fiji to directly meet with his defence counterpart Inia Seruiratu.
The trip is positioned against China's growing influence in the Pacific after Beijing signed a security pact with the Solomon Islands.
"Our region is increasingly facing both traditional and non-traditional threats to our shared security," Mr Marles said in a statement ahead of his departure.
"The Pacific family is stronger when we respond together, by enhancing co-ordination, sharing information and improving interoperability between our countries and our defence forces."
Mr Marles heads to Tonga after returning from Papua New Guinea, where he sought to strike a security deal with Australia's closest neighbour.
Such an agreement would allow personnel from both countries to work more closely together.
Ministers will also tour tsunami-affected areas in Tonga and Mr Marles will then visit a disaster relief camp in Fiji, as Australia conducts a review of its humanitarian aid spending.
"Australia and Fiji's defence relationship is enduring and strong," he said.
"I look forward to the opportunity to visit Fiji and meet with Minister Seruiratu again, as we work to enhance our defence partnership."
