Australian defence scientists have helped test robotic vehicles with the United States and United Kingdom under the AUKUS security pact.
The trial was conducted at Cultana Training Area northwest of Adelaide in late 2023, but only came to light on Tuesday in a statement published by the US Defence department.
The test was to gauge autonomous vehicle behaviour when under attack.
Australian scientists subjected the vehicles to electronic warfare, navigation and timing assaults.
The three-way deal between Australia, the UK and US was struck in 2021.
Under the agreement, the US will sell up to five Virginia-class submarines in the 2030s, but the sales will be subject to approval.
Australian Strategic Policy Institute senior analyst Malcolm Davis said AUKUS would be troubled if it failed to deliver early on.
"It's really important that we actually accelerate and expand these sorts of efforts to actually deliver these sorts of capabilities into operational services the sooner rather than later," he told AAP.
"We can't be thinking along 10-year time-frames with some of these things."
Dr Davis said these autonomous systems should be introduced into operational service within five years.
"For that to happen we need to go full speed on testing, developing these systems," he said.
Dr Davis said the trials needed to lead to capabilities being deployed, as Australia had always moved at a "snail's pace".
"Because the strategic environment around us is deteriorating rapidly, our capability acquisition has to be equally rapid or faster," he said.
