Defense chiefs of Japan, the United States and Australia have agreed to expand joint drills as China steps up its maritime activities. The officials also said they oppose attempts to unilaterally change the status quo in the East and South China seas.

Japanese Defense Minister Hamada Yasukazu, US Defense Secretary Lloyd Austin and Australian Defense Minister Richard Marles met in Singapore on Saturday on the sidelines of a major security conference, the Shangri-La Dialogue.

In a joint statement released after the meeting, the ministers expressed serious concern about the increasingly severe security environment in the East China Sea.

The statement says the officials "strongly opposed any destabilizing and coercive unilateral actions that may escalate tensions in the East China Sea."

According to the statement, the ministers committed to enhancing defense cooperation among the three countries, including conducting trilateral F-35 joint strike fighter training in Australia and regularizing asset protection missions for the US forces and the Australian defense force by Japan Self-Defense Forces.

They also confirmed that Australia and Japan would work closely together, and with the United States, as Japan introduces counterstrike capabilities and Australia invests in long-range strike capabilities.