Defence Minister Linda Reynolds has met her Japanese counterpart Kishi Nabuo in Tokyo where both warned against attempts to "change the status quo by coercion" in the South China Sea.
In a joint statement on Monday night the ministers said their nations would continue to coordinate closely on the security situation in the region.
They affirmed the importance of upholding freedom of navigation and overflight.
Without naming China they reaffirmed their "serious concern" about the militarisation of disputed islands and reefs, "dangerous or coercive use" of coast guard vessels and "maritime militia" and efforts to disrupt other countries' resource exploitation activities.
"The ministers reinforced their strong opposition to any attempts to unilaterally change the status quo by coercion in the South China Sea," their statement said.
They emphasised the importance of peaceful resolution of disputes in accordance with international law, including the United Nations Convention on the Law of the Sea (UNCLOS).
The ministers also shared their strong concern over North Korea's violations of multiple UN Security Council Resolutions, including repeated launches of short range ballistic missiles.
They reaffirmed their commitment to achieve the complete and verifiable dismantling of all of North Korea's nuclear weapons, other weapons of mass destruction and ballistic missiles of all ranges.
The ministers also resolved to forge deeper links across a range of defence and security interests, including joint exercises and exchange of personnel and to continue to work closely with the US and other Indo-Pacific partners.
Australian Associated Press