The Philippines, the United States, Japan and Australia will conduct a joint deployment of maritime forces on Sunday, April 7, to conduct a joint maritime activity within the West Philippine Sea.

The Defense Departments of the four countries said in their joint statement that the Maritime Cooperative Activity (MCA) will demonstrate their "collective commitment to strengthen regional and international cooperation in support of a free and open Indo-Pacific."

This comes as China continues its claim and conducts aggressive actions in the West Philippine Sea, prompting Philippine allies, including the US, Japan and Australia, to affirm their support for the Philippines' territorial integrity.

"Australia, Japan, the Philippines and the United States uphold the right to freedom of navigation and overflight, and respect for maritime rights under international law, reflected in the UN Convention on the Law of the Sea (UNCLOS)," their statement released Saturday, April 6, read.

The MCA will be conducted by maritime and air force units of the four countries "in a manner that is consistent with international law as well as domestic laws and rules of respective nations."

The Philippines, the US, Japan and Australia also gave assurance that they will give regard to the safety of navigation and the rights and interests of other states as well as demonstrate professional interactions among maritime and air forces.

"Ultimately, the MCA will strengthen the interoperability of our defense/armed forces doctrines, tactics, techniques, and procedures," they added.

The four countries said they are standing with all nations in safeguarding the international order based on the rule of law, which they asserted is "the foundation for a peaceful and stable Indo-Pacific region."

"Our four nations reaffirm the position regarding the 2016 South China Sea Arbitral Tribunal Award as a final and legally binding decision on the parties to the dispute," they said.

Japanese Defense Minister Kihara Minoru said Tokyo's participation "is directly related to the peace and stability of the region and is a legitimate concern of the international community."

"Japan opposes any unilateral changes to the status quo by force, such attempts as well as any actions that increase tensions in the South China Sea," he said.

US Defense chief Lloyd Austin believed every country should be free to conduct lawful air and maritime operations.

"These activities with our allies Australia, Japan, and the Philippines underscore our shared commitment to ensuring that all countries are free to fly, sail, and operate wherever international law allows," he said.

Australian Deputy Prime Minister and Defense Minister Richard Marles said Canberra is committed to work with partners "to maintain the global rules-based order."

"We recognize that respect for national sovereignty and agreed rules and norms based on international law underpin the stability of our region," he said.

"The Comprehensive Archipelagic Defense Concept (CADC) that we are implementing includes strengthening and deepening cooperation and interoperability with all nations, big and small, to maintain regional peace and stability as well as good order at sea based on international law, principally UNCLOS," added Philippine Defense chief Gibo Teodoro.