Mr Marles, who is also the defence minister, held security discussions in Wellington on Thursday with his New Zealand counterpart Andrew Little, Deputy Leader Carmel Sepuloni, and Finance Minister Grant Robertson.
A major part of the AUKUS agreement is delivering nuclear-powered submarines using American and British technology for Australia, but there are non-nuclear aspects to the deal.
While New Zealand's potential involvement with AUKUS wasn't discussed at the meeting, it was a "backdrop" to the trans-Tasman relationship, Mr Little added.
In a press conference after the discussions, Mr Marles said Australia was "open to expanding" the second pillar to New Zealand.
"AUKUS is about the sharing of technology," he told reporters.
"AUKUS pillar two ... which is those technologies beyond submarines, we need to get runs on the board so that this is an arrangement that is attractive to others."
A second pillar to the partnership, which is of interest to the NZ government, covers the sharing of advanced military technologies, including quantum computing and artificial intelligence.
The meeting comes ahead of the inaugural Australia-New Zealand foreign and defence ministers meeting in June.
Mr Little has said New Zealand is interested in exploring participation in the second pillar, which could include surveillance and radio technology.
NZ is concerned AUKUS may jeopardise the Treaty of Rarotonga which designates large swathes of the Pacific free of nuclear weapons.
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