Australia's defence minister aimed to reassure Thailand on Friday that plans to acquire a new fleet of nuclear submarines would enhance "collective security" in the region after neighbouring countries voiced concerns.

The submarine issue came up during a visit to Manila earlier this week, Defence Minister Richard Marles told AFP in an interview, and was also on the agenda for Friday's talks with Thai Prime Minister Prayut Chan-O-Cha, who is responsible for defence.

"The point I'll be making to the prime minister is about contributing to the collective security of the region," Marles said ahead of the meeting.

"It's about building balance, and through that contributing to peace and stability of the region."

Australia has been weighing whether it wants the United States or Britain to supply the new nuclear subs, with Prime Minister Anthony Albanese expected to announce a decision in Washington next month at a meeting with both countries' leaders.

Malaysia and Indonesia have expressed concerns about the acquisition, warning against an arms race.

But Marles said Australia wanted to build a "sense of confidence" about the plan.

The previous Australian government tore up a contract to buy French diesel-powered subs in favour of US or British nuclear ones -- a move that angered Paris.

The submarine deal emerged out of a new security pact between Australia, Britain and the United States -- dubbed AUKUS -- aimed at countering a rising China.

The multi-billion dollar project and a new yet-to-be released strategic defence review marked a huge gear shift in Australia's defence policy, Marles said.

He confirmed the meeting in Washington next month would also detail an interim measure to fill Australia's looming submarine capability gap as its ageing Collins Class fleet nears retirement.

Last year, French President Emmanuel Macron said that an offer to cooperate with Australia on submarines still stood, despite the bitter row over the cancelled contract.

But Marles said Friday that "acquiring a conventionally powered submarine is not going to form part of any solution".