Professor John Blaxland, of the Australian National University's Strategic and Defence Studies Centre, said it would be akin to the relationship the United States has with Palau, the Marshall Islands and Micronesia, and New Zealand has with Niue and the Cook Islands.

Australia's "compacts of association" would be with Kiribati (population 115,000), Tonga (107,000), Tuvalu (11,000) and Nauru (11,000).

"That means Australia would offer residency rights and potentially citizenship to just over 244,000 people and help administer and guarantee sovereignty to a cumulative [exclusive economic zone] of over 5.118 million square kilometres," Professor Blaxland said.

"Australia would gain economically and politically from bolstering security and stability in the region, while also helping to limit the prospect of destabilising external interference."

He stressed it must be about dignity and mutual benefits to avoid being seen as "a neo-colonial land grab".

"The proposal outlined here is to offer a compact that is substantive, respectful, inclusive and voluntary," he said, in a submission to a parliamentary inquiry into Australia's defence relationship with the Pacific.

Former prime minister Kevin Rudd suggested something similar last year, calling for a "formal constitutional condominium" similar to the arrangement with Norfolk Island. He also prepared a Cabinet paper on the idea in 2012. His call was not well received, with Tuvalu's prime minister accusing him of "imperial thinking".

But Professor Blaxland said a closer relationship would bring enormous benefits to the Pacific nations, helping them monitor their seas, which were being exploited dramatically by foreign fishing and sea bed exploration.

The islanders had had a cultural predisposition to work with Australia and most would be much more comfortable with a trusting, two-way relationship with Australia than with China, he said. He predicted they could "warmly embrace" the idea if Australia was "big enough" to meet their needs on the environment and climate change, and if it changed its attitude of "flittering between haughty and disengaged".

It should be done "very much with a "please consider" mindset, not a "here's what you need to do", haughty neocolonialist one," he said.

"The ball's in the court of the individual Pacific Islands. If they want this they can discretely quietly approach their high commissioner and say ... we are interested."

A similar but less all-encompassing arrangement also should be considered for the larger Pacific states, including Vanuatu (population 270,000), Solomon Islands (600,000) and Fiji (898,000), he said, suggesting patrolling of their seas and residency rights in Australia.

Professor Blaxland also predicted pushback from islanders who had a vested interest in the Chinese deals that had been made in the islands, but said a closer relationship with Australia would not preclude Chinese money. Any pushback should not be allowed to "deflect patriots of those islands and from Australia from seeing beyond the bluster to seeing the common shared interests that would be served by this proposal", he said.

"When you put together the overlap between great power contestation, looming environmental catastrophe and a spectrum of governance challenges, the Pacific Islanders and Australians have more in common and a greater urgency and need for collaboration than in living memory."