Defense chiefs of the Philippines, the United States, Japan and Australia have slammed China's aggressive actions in the South China Sea, prompting them to line up recent more quadrilateral maritime actions to assert rules-based order in the waters.

Department of National Defense (DND) Secretary Gibo Teodoro, US Defense Secretary Lloyd Austin, Japanese Defense Minister Kihara Minoru, and Australian Defense Minister Richard Marles met in Hawaii for their second ministerial meeting, where they discussed their concerns on developments in the Indo-Pacific.

In a press conference on Friday, May 3, Marles said their move to conduct more maritime exercises "is about the assertion of a global rules-based order," a way which their countries can work together.

The four defense chiefs' meeting followed the recently held Maritime Cooperative Activity (MCA) among their nations, where they strengthened the interoperability of their defense and armed forces doctrines, tactics, techniques, and procedures.

On April 7, Filipino, American, Japanese and Australian troops conducted joint maritime drills in the West Philippine Sea amid China's repeated aggression against the Philippines in the waters.

In the readout of their meeting that was released Saturday, May 4, the four Defense chiefs expressed serious concern about the situation in the East and South China Seas as they also strongly objected to the dangerous use of coast guard and maritime militia vessels in the South China Sea.

Meanwhile, Austin tagged as “irresponsible behavior” China’s actions that recently injured the crew of the Philippine vessels and damaged their ships.

"They reiterated serious concern over the PRC's (People's Republic of China's) repeated obstruction of Philippine vessels' exercise of high seas freedom of navigation and the disruption of supply lines to Second Thomas Shoal, which constitute dangerous and destabilizing conduct," the readout stated.

Citing the importance of rule of law reflected on the United Nations Convention on the Law of the Sea (UNCLOS) and the 2016 Arbitral Ruling, they vowed to work together that the rules-based order will be followed.

Hence, they committed to bolster alliance in support of regional security and stability as they saw opportunities to further advance defense cooperation through continued maritime cooperation in the South China Sea, enhanced procedures to enable coordination and information sharing arrangements and strengthening capacity building.

"We’re clear-eyed about the challenges that exist throughout the region.. and so we'll need to continue to work together, to increase interoperability, to make sure that we share information, share intelligence," Austin said.

Austin said they are looking to have more maritime exercises and activities among their countries, while Kihara said their meeting and statement "is not directed towards any specific or particular nation."

Rather, it is towards the nations which are trying to change the status quo by force, he said.

"We also want to pursue coordinated security assistance to the Philippines that will boost interoperability and help the Philippines achieve its defense modernization goals," Austin added.