Australian officials say they don't believe there is merit in expanding the nuclear non-proliferation treaty to nuclear-powered submarines.
Indonesian officials have said they would seek a "fourth pillar" to include the non-peaceful usage of nuclear technology, closing a "loophole" exposed by Australia's nuclear-submarine deal with the US and UK.
They say other countries could seek to follow Australia, which would be the first non-nuclear weapons state to acquire nuclear submarines.
Foreign affairs department officials rejected the need to expand the treaty, saying the acquisition of nuclear-propelled submarines was in accordance with Australia's non-proliferation requirements.
"We would be very cautious that the non-proliferation treaty be opened up for any reason," department assistant secretary Amanda Gorely told a Senate estimate hearing on Thursday.
"We do not believe it is necessary to open it up to deal with nuclear propulsion."
The admission Australian officials were not given a heads up about the treaty push comes in light of Indonesian indignation over being informed about Australia's new trilateral security pact through media reporting.
The Indonesians raised concerns about the potential for an arms race in the region after Australia announced its plans to acquire nuclear-powered submarines through the AUKUS partnership.
Prime Minister Scott Morrison told leaders from the Association of Southeast Asian Nations on Wednesday the new arrangement did not change Australia's commitment to the region.
Mr Morrison reiterated Australia had no intention of acquiring nuclear weapons and remained deeply committed to nuclear non-proliferation.
Foreign Minister Marise Payne defended how the government handled the AUKUS announcement, amid criticism key allies were notified too late.
Senator Payne said the leaking to the media of details about a partnership between Australia, the US and UK before the official announcement was "regrettable".
The foreign affairs department advised the minister that countries including Japan, Indonesia, India, South Korea, New Zealand, France and Canada be notified prior to the official announcement.
Subsequent leaks to the media the night before derailed this timeline, resulting in some allies finding out about the new security arrangement through the press rather than diplomatic channels.
Officials did not confirm how far ahead of the announcement it recommended key allies be informed.
Senator Payne said she would prefer sensitive information about Australia's security decisions not be canvassed in the media before they are due to be officially announced.
"I think that is regrettable ... given that the formal announcement was the (timeline we were working towards) with a number of key partners."
Senator Payne and department deputy secretary Justin Hayhurst said they were unaware of any complaints by the Indonesian government about how late they were told about the AUKUS partnership.
Australian Associated Press