Former prime minister Kevin Rudd fears Australia has taken the foot off the accelerator when it comes to ties with Indonesia.
There are expectations South East Asia's biggest economy could climb to the top seven in global rankings by 2030, up from its existing spot of 16.
Mr Rudd said a large-scale effort was needed to go beyond "sporadic" interactions.
"There is a real danger in the long-term drift in the Australia-Indonesia relationship," Mr Rudd told AAP.
"It requires a massive effort from Australia, not just a thought every other month or two."
Mr Rudd said he understood Indonesian President Joko Widodo and Prime Minister Malcolm Turnbull had a reasonable working relationship.
"But what I observe from my own dealings with Jakarta, is that the closeness of the relationship we enjoyed with President (Susilo Bambang) Yudhoyono is less evident," he said.
"We need to work doubly hard to rebuild that relationship in the long-term future."
His comments came in the wake of the two countries failing to meet a deadline late last year on sealing a free trade agreement.
Hopes the deal could be reached before a special Australian summit with Association of South East Asian Nation leaders in Sydney next month are coming up against some strong protectionist sentiment in Indonesia.
Mr Rudd also pointed to the need to further ramp up counter-terrorism and anti-radicalisation cooperation, in light of jihadist fighters returning from Iraq and Syria.
"This should be the absolute centrepiece for strategic cooperation," he said.
"The last thing we want to see is yet another terrorist attack against Australians as soft targets in Indonesia."