Prime Minister Anthony Albanese and Japan's Prime Minister Fumio Kishida have signed a joint security declaration which substantially scales up defence cooperation and commits both countries to "consulting" with each other if they face potential security threats.
The two men signed the new agreement at the annual Australia-Japan Leaders' Meeting in Perth, substantially updating a 2007 pact signed by John Howard and Shinzo Abe.
The summit is the fourth for the leaders since Mr Albanese took office in May.
"The level of interaction which we have reflects very much the special strategic partnership that Australia and Japan have. We two countries really matter to each other now more than ever," Mr Albanese said in a press conference on Saturday.
The updated joint declaration charts a path for closer cooperation between Australia and Japan over the next decade, reflecting the strong and growing strategic alignment of the two countries.
It says Australia and Japan "will consult each other on contingencies that may affect our sovereignty and regional security interests, and consider measures in response".
That echoes some of the language used in the ANZUS treaty between the United States and Australia — although, unlike that pact, this joint declaration is not a legally binding treaty.
Bryce Wakefield from the Australian Institute of International Affairs (AIIA) said that while the section on consultation inched the two countries "towards a mutual security guarantee", it did not make explicit promises or go as far as US security treaties with Japan and Australia.
"For Japan, this is a new way about thinking about security," he told the ABC.
"It has been so heavily reliant on the US-Japan security alliance in the past, but it's now leaning towards a more networked idea of security with key partners like Australia."
The declaration also says the two countries will "expand and deepen practical cooperation and further enhance interoperability between the Australian Defence Force and the Japan Self-Defense Forces through more sophisticated joint exercises and operations, multilateral exercises with partners, mutual use of facilities including maintenance, asset protection, and personnel links and exchanges".
Mr Albanese said the document sent a "strong signal" of the "strategic alignment" between Australia and Japan.
"Our commitment to consult each other on contingencies is a natural step in efforts to support the security and stability of the region," he said.
"It shows the responsibility we share for security in our region and towards one another."
Mr Kishida said on Saturday he and Anthony Albanese agreed that ties between the two US allies had reached a new level given their close cooperation in security, energy and natural resources.
"[The agreement] will be a compass that shows the direction of bilateral security and defence cooperation for the next 10 years," Mr Kishida told a news conference in Perth.
Mr Albanese and Mr Kishida also discussed climate change, expressing support for a regional transition to net zero carbon emissions and boosting investment in clean energy tech.
"Both our countries are committed to net zero by 2050," Mr Albanese said.
The joint declaration also does not include any specific references to armed attacks such as those found in ANZUS, which says the US and Australia will " act to meet the common danger" if under assault.
Among those efforts, the leaders agreed to help build secure supply chains between the two nations for "critical minerals, including those that are required for building the green technologies of the future," Mr Albanese said.
"This partnership will mean we build secure supply chains, promote investment, develop Australia's domestic sector and make sure Japan's advanced manufacturers have the critical minerals they need."
As well as building a framework for secure supply chains, the partnership would promote information sharing and collaboration, including research, investment and commercial arrangements between Japanese and Australian critical minerals projects, the Australian government said in a statement.
'Central pillar of cooperation'
Mr Kishida told reporters that signing the updated joint security declaration was one of the largest achievements of his visit.
"I expressed my determination that all necessary options for the defence of our country, including the so-called counterstrike capability, would become contemplated and Japan's defence capability will be fundamentally reinforced in the next five years, which is supported by Anthony," he said.
The Japanese leader said the two nations had been working to achieve a free and open Indo-Pacific under "an increasingly severe strategic environment".
"Through this experience, the bonds that tie Japan and Australia together have become much stronger. And our two countries have become the central pillar of cooperation among like-minded countries," he said.
Australia is a major supplier of iron ore, coal and gas to Japan.
Locating the meeting in Perth, 3,700 kilometres from Canberra, was meant to showcase Western Australia's importance in supplying Japan's energy needs, including renewable energy. The state is also a key source of beef and wheat to Japan.
Canberra and Tokyo recently bolstered security ties in response to China's growing military strength in the region. In May, Mr Kishida and Mr Albanese pledged to work toward a new bilateral declaration on security cooperation.
A previous joint declaration outlined security cooperation in areas such as counter-terrorism and North Korea's missile and nuclear weapons programmes.
The two countries in 2014 elevated their relationship to a "Special Strategic Partnership".
'Highly significant'
The Executive Director of the Australian Strategic Policy Institute, Justin Bassi, said the joint declaration was "highly significant" and "not merely an anodyne summary of the bilateral relationship".
"This is a clear description of its intimacy in relation to how the two countries see the world, their roles in it and the challenges that must be faced head-on," he said.
"The commitment to consult on contingencies and consider response measures further elevates the partnership and should be viewed as a clear sign of both countries' assessment of the strategic environment.
"And it is noteworthy that this commitment is in the point that focuses on the next 10 years."
