During the meeting on the sidelines of the Shangri-La Dialogue in Singapore, US Defense Secretary Lloyd Austin, Japanese Defense Minister Yasukazu Hamada, Australian Defense Minister Richard Marles and Philippine Defense Secretary Carlito Galvez "discussed regional issues of mutual concern and opportunities for expanding cooperation", according to a statement issued after the meeting.
The ministers agreed to strengthen security cooperation in efforts to promote a free and open Indo-Pacific. The ministers also "affirmed that they have a vision of a "free and open Indo-Pacific" and work together to ensure that vision continues to develop," according to Japan's defense ministry.
The quadrilateral meeting comes as Tokyo, Washington and Canberra have all stepped up defense cooperation with Manila, amid growing concerns about China's growing military presence in the South China Sea and East China Sea, as well as escalating US-China tensions.
Earlier on the same day, Ministers Hamada, Austin and Marles held a separate meeting. During the trilateral meeting, they opposed unilateral efforts to change the status quo in the East China Sea and South China Sea, according to NHK.
The ministers agreed to expand joint exercises and strengthen defense cooperation between the three countries, including conducting training with F-3 fighter jets in Australia.
They also confirmed that Australia and Japan will work closely with each other and with the US, as Japan wants to achieve counter-attack capabilities and Australia invests in long-range strike capabilities.