But Penny Wong pledged Australia would engage in partnerships of mutual respect and co-operation to ensure nations always maintain their sovereignty.
Australia and Vanuatu have signed a new bilateral security pact but the details have yet to be publicly released.
Speaking in Vanuatu alongside Pacific Minister Pat Conroy and coalition counterparts Simon Birmingham and Michael McCormack, Senator Wong said regional security was a shared responsibility.
"We all have a responsibility to ensure our sovereign decisions enhance the security of all members of the Pacific and we're deeply proud to be the Vanuatu principal security partner of choice," she told reporters in Port Vila.
"Decisions about how a country wishes to engage with (Australia), what level of co-operation, what priorities that country articulates are issues for that sovereign nation."
The delegation also took part in a handover of a new wharf and police boat.
The wharf was built as part of Australia's Pacific maritime security program.
Liberal senator Simon Birmingham echoed the foreign minister's remarks and said the two nations were at their strongest in a challenging and contested world when they stood together.
"We stand together as nations at the forefront of delivering ... on Pacific-led solutions to security and stability in the Pacific and that is something we are all deeply committed to continuing to do," he said.
"Governments in Australia, whatever their composition - Labor, Liberal or National - make sure that we build upon the partnerships that are effectively underpinning relations in our region."
Action on climate change continues to be part of security conversations with Pacific leaders and Palau's president has urged Australia to increase its action on reducing emissions.
The delegation is set to visit Palau after Vanuatu before travelling to Micronesia.
Palau president Surangel Whipps Jr said he applauded Australia's actions in increasing its emissions reduction target to 43 per cent by the end of the decade but wanted to see it go further.
"We would like to see 50 per cent reduction by 2030," he told ABC Radio on Tuesday.
"That's what the Pacific called for ... going from 30 per cent to 43 per cent is a big step in the right direction.
"We expect leadership, we expect commitment and the understanding that we are going under. We have islands that will disappear if we don't raise those ambitions and keep below 1.5 (degrees)."
After China sought to set up security pacts with multiple Pacific nations, Mr Whipps said economic coercion should not be used to influence policies.
"There's a lot of Chinese investment in Palau. I think they're the number one foreign investor now. This changes the political dynamic," he said.
"There's been pressure on us to switch to China and Palau has been strong and saying that we are enemies to none and friends to all and no one should tell us who our friends should be."
Mr Conroy said while there was competition in the region, it was critical for Pacific nations to be able to work together.