THE leaders of Australia and Japan hailed the signing of a “historic” defence treaty today as China warned that the pact must not undermine peace in the region.

The Reciprocal Access Agreement is only Japan’s second such agreement and comes just months after Australia, Britain and the United States signed their Aukus security pact.

Japan is seeking to sign a similar treaty with France and Britain, according to the Kyodo news agency, which said that the two nations “have been increasing defence co-operation with Tokyo in response to an increasingly assertive China.”

Australian Prime Minister Scott Morrison said the agreement would “contribute to a secure and stable Indo-Pacific” as China expands its military and economic influence in the region.

He described it as “a pivotal moment for Australia and Japan” and said it would “underpin greater and more complex engagement in operability between the Australia Defence Force and Japan Self-Defence Forces.”

The agreement was signed during a virtual summit between the two nations after more than a year of talks.

It will allow for joint military exercises and the faster deployment of Japanese and Australian military personnel, as well as easing restrictions on the transport of weapons and supplies for joint training and “disaster relief operations.”

Japanese Prime Minister Fumio Kishida said the pact was “a landmark instrument which will elevate security co-operation between the nations to new heights.”

However, critics warn that the agreement represents a new frontier in the US-led cold war on China as it seeks to strengthen the “Quad” — an anti-China group of four nations: the US, India, Japan and Australia.

Mr Morrison noted that Japan and Australia’s heightened co-operation “also includes an expanding agenda for the Quad with India and the United States, and our shared technology-led approach to reducing carbon emissions.”

Formed in 2007, the group of nations was revived by former US president Donald Trump in 2017 when he agreed that the US would take part in joint patrols of the South China Sea to counter so-called “Chinese aggression.”

In 2020, the Quad’s warships and planes carried out military exercises in the Indian Ocean in its biggest show of strength so far.

China then warned against a Quad framework aimed at building an “Indo-Pacific Nato,” warning that the strategy was “a huge security risk” for the region.

Chinese Foreign Ministry spokesman Wang Wenbin said he hoped that the new agreement would not lead to an escalation of hostilities.

“State-to-state exchanges and co-operation should be conducive to enhancing mutual understanding and trust among countries in the region and safeguarding regional peace and stability, rather than targeting or undermining the interests of any third party,” he said.

“We hope that the Pacific will be an ocean of peace, not a place to make waves.”