The United States and Australia have tackled China’s aggression against the Philippines in the South China Sea as their leaders met in Washington to bolster alliance for countries in the Indo-Pacific.

President Joe Biden and Prime Minister Antony Al​banese on Wednesday (US time) opposed destabilizing actions in the waters, including unsafe encounters at sea and in the air as well as the militarization of disputed features, the dangerous use of coast guard vessels and maritime militia​.

Both leaders mentioned in particular actions that "interfere with routine Philippines maritime operations around Second Thomas Shoal" as well as the "efforts to disrupt other countries' offshore resource exploitation."

"We also recognize that the 2016 South China Sea Arbitral Award is final and legally binding on the parties in that proceeding, and we are concerned about China's excessive maritime claims that are inconsistent with international law, as well as unilateral actions that may raise tensions and increase the risk of miscalculation in the region," their joint statement read.

Biden and Albanese said they are committed to work with their partners in supporting regional maritime security and uphold international law as they stressed the importance of all states "being able to exercise rights and freedoms in a manner consistent with international law as reflected in the United Nations Convention on the Law of the Sea (UNCLOS), including freedom of navigation and overflight."

​Meanwhile, during their joint press conference, Biden also reiterated Washington's defense commitment to the Philippines as he recalled the recent maneuver made by Chinese vessels in the Ayungin Shoal that led to a collision with a Philippine boat.

He said that PRC vessels acted dangerously and unlawfully "as our Philippine friends conducted a routine resupply mission within their own — their own exclusive economic zone in the South China Sea."

"I want to be very clear: The United States' defense commitment to the Philippines is ironclad.  The United States' defense agreement to the Philippines is ironclad," he said.

"Any attack on the Filipino aircraft, vessels, or armed forces will invoke...our Mutual Defense Treaty with the Philippines," Biden added.

The Philippines has shared its commitment with the US and Australia is ensuring peace and stability in the region and in maintaining rules-based order, particularly with regards to disputes in the South China Sea.

In September, the Philippines and Australia expressed the importance of their role as maritime nations and declared their commitment to maintain that freedom of navigation and overflight in the regional waters is respected, in line with international law.

During Albanese's visit, he and President Marcos signed a joint declaration, where they reiterated, among other pledges, to continue with their plan to conduct joint patrols in the South China Sea—a highly contested area at risk of geopolitical tension—to secure the waters against aggressors.