Senior cabinet minister Marise Payne is not ruling out buying German-made submarines to fill a capability gap while Australia waits for a French-designed fleet.
Senator Payne was defence minister when the coalition decided to team up with France on a $90 billion program to build Australia's next fleet of submarines, which are due to enter service in the 2030s.
But the navy is reportedly examining whether German boats could fill a gap in the interim, as tensions grow with the French company.
Senator Payne, now foreign minister, said it was not for her to rule the German option in or out.
"The Attack Class program is well under way and our partners in France are devoting a very great deal of effort to deliver that project," she told ABC radio.
"Our challenge is to build, and our commitment is to build, a regionally superior submarine capability and that is what we are undertaking."
Senator Payne said the Department of Defence remained strongly committed to building the submarines in Adelaide.