Secretary of War Pete Hegseth hosted Richard Marles, Australia's deputy prime minister and defense minister, at the Pentagon today to commemorate the 75th anniversary of the ANZUS Treaty, the collective defense agreement among Australia, New Zealand and the United States, according to the Department of War.
The ANZUS Treaty, signed September 1, 1951, established a collective agreement between the three countries to protect security throughout the Pacific region. Over the past 30 years, the treaty has served primarily as an instrument of bilateral cooperation between the U.S. and Australia, as well as separate bilateral cooperation between Australia and New Zealand.
During the meeting, Hegseth and Marles discussed how both nations are committed to advancing the alliance and strengthening deterrence throughout the Pacific region. Hegseth emphasized the importance of capable allies contributing to collective defense by investing in their own sovereign security and noted strong alignment between the U.S. and Australia's national defense strategies.
"We share a common understanding of the complex threat picture in the world today and the need for allies to both plan together but also ensure our capabilities match and are complementary – if, and when, military conflict was to have to take place," Hegseth said.
The U.S. and Australia have a long history of joint military exercises. In July, the air forces of the two countries joined with the Japan Air Self-Defense Force to conduct training in Australia's Northern Territory as part of Exercise Southern Cross. In June, U.S. Marines joined Australia and Japan's respective defense forces for Exercise Southern Jackaroo. In 2025, both militaries participated in Exercise Talisman Sabre, a biennial flagship exercise that drew more than 35,000 personnel from 19 nations across Australia and Papua New Guinea.
Recent developments include the arrival of U.S. Navy sailors in Western Australia to support Submarine Rotational Force – West, a joint military plan to station U.S. and U.K. nuclear-powered submarines in Western Australia ahead of operations in 2027.