Foreign Minister Penny Wong announced A$286.5 million ($186.7 million) in funding for ASEAN projects in areas including maritime security, amid tensions over China's growing assertiveness and its disputed claims to the South China Sea.
"We face destabilising, provocative and coercive actions including unsafe conduct at sea and in the air," Wong said in a speech at the summit, without naming China.
"What happens in the South China Sea, in the Taiwan Strait, in the Mekong subregion, across the Indo-Pacific, affects us all."
Melbourne is hosting leaders and officials from the 10-member Association of Southeast Asian Countries (ASEAN) for a summit from Monday to Wednesday. ASEAN member Myanmar was excluded due to the ongoing conflict in the country.
Australia is using the 50th anniversary of its ties with ASEAN to bolster ties with the region as it deals with China's growing diplomatic and military reach.
China claims almost the entire South China Sea, a conduit for more than $3 trillion of annual ship-borne commerce, including parts claimed by ASEAN members the Philippines, Vietnam, Indonesia, Malaysia and Brunei. The Permanent Court of Arbitration in 2016 said China's claims had no legal basis.
Speaking alongside Wong, Philippines Secretary of Foreign Affairs Enrique Manalo said the South China Sea was of strategic importance and had a promising future as long as "nations in the region resolved to uphold cooperation over confrontation".
Australia and the Philippines began their first joint sea and air patrols in the South China Sea in November.
The Philippines is ramping up efforts to counter what it describes as China's "aggressive activities" in the South China Sea, which has also become a flashpoint for Chinese and U.S. tensions around freedom-of-navigation operations.
MYANMAR CONFLICT
Just over a month since ASEAN foreign ministers called for an end to the bloody conflict in member state Myanmar, hundreds of protesters gathered outside the downtown Melbourne venue to call for concrete punitive action against the military junta.
ASEAN has barred Myanmar's top generals from attending its meetings until they commit to a peace plan, but has stopped short of further action. The junta has been furious over what it calls ASEAN's interference in its internal affairs.
One activist called for international recognition of the parallel National Unity Government, which controls militias in the country.
"ASEAN countries and Australia please act. We need action, please don't wait for (ASEAN's) plan, it is useless," activist Yuyu Chit said.
