Approximately 1,200 Australian soldiers and 560 Filipino marines took part in military exercises that involved storming a beach.
Marles made the announcement on Friday while observing some 2,000 Australian and Philippine defence personnel, as well as United States Marines, participate in amphibious landing and air assault drills as part of joint exercises also attended by Philippine President Ferdinand Marcos Jr.
The joint drills come amid renewed tensions between Manila and Beijing in the South China Sea and involved troops arriving in amphibious assault vehicles, by parachute and on board US Osprey aircraft to storm a beach.
Two advanced Australian F-35 fighter jets provided close air support, and Australian warships secured the surrounding waters.
The air, sea and land drills, the first large-scale joint exercise between Australia and the Philippines, simulated retaking an enemy-controlled island.
President Marcos told reporters the Philippines wants a closer working relationship with the militaries of regional neighbours.
“It is an important aspect of how we prepare for any eventualities, considering there have been so many events that attest to the volatility of the region,” he told a news conference after the drills.
Marles said after the drills that the first joint patrols of the South China Sea by the Australian and Philippine navies would “happen soon”.
He also reiterated support for a 2016 ruling by an arbitration tribunal in The Hague under the UN Convention on the Law of the Sea that largely invalidated China’s claim to virtually the entire South China Sea, and upheld the Philippines’ control over resources in a 200-nautical-mile (equivalent to about 370km) exclusive economic zone.
China refused to participate in the arbitration and continues to defy the ruling, maintaining its claim to most of the sea.
“A whole lot of damage can be done to Australia before any potential adversary sets foot on our shores, and maintaining the rules-based order in Southeast Asia, maintaining the collective security of Southeast Asia, is fundamental to maintaining the national security of our country,” Marles said in an interview earlier on Friday.
The US, Australia and the Philippines are among the most vocal critics of China’s increasingly aggressive and confrontational actions in the disputed waters, but the Philippine military said Beijing was not the envisioned target of the combat drills on Friday.
In the latest flare-ups between the Philippines and China in the disputed waters, a Chinese coast guard ship used a water cannon on August 5 to try to block a Philippine supply run at Second Thomas Shoal, where Filipino troops are stationed.
Australia and the US expressed support for the Philippines and raised strong concerns over the Chinese coast guard ships’ actions.
Washington renewed a warning that it was obligated to defend the Philippines, its oldest treaty ally in Asia, if Filipino forces, ships and aircraft come under attack, including in the South China Sea.
Two Philippine supply boats managed to pass the Chinese blockade on Tuesday in a tense confrontation witnessed by journalists.
China has warned the US not to meddle in what it says is a purely Asian dispute.
The Philippines, Malaysia, Vietnam, Brunei and Taiwan all have claims to certain areas of the South China Sea.