The Marine Corps is making good on a 2011 promise to send 2,500 Marines annually to Australia as part of a strengthened alliance in the face of Chinese expansionism, with over 1,000 Marines and 17 aircraft from Hawaii in the mix.

Approximately 800 Hawaii Marines from the 3rd Battalion, 3rd Marines, who deployed to Okinawa last month will relocate to northern Australia this month to be part of Marine Rotational Force-Darwin and train with Australian counterparts, officials said.

Some 1,700 Marines — including 300 aviation personnel from Hawaii and others from units in California — made up an earlier arriving group.

Gradually ramping up its presence Down Under, the Corps sent about 200 Marines in 2012 and increased that to nearly 1,600 last year.

The increase to 2,500 Marines for the first time “is a tangible demonstration of the United States’ sustained commitment to the Australia-U.S. alliance and to maintaining a free and open Indo-Pacific region,” said 1st Lt. Colin Kennard, a spokesman for Marine Rotational Force-Darwin.

The United States and Australia, meanwhile, are scrambling to shore up relationships in the Western and South Pacific where China has been making military inroads and investing millions in construction projects, buying influence in the process.

China “seeks to reorder the region to its advantage by leveraging military modernization, influence operations and predatory economics to coerce other nations,” former acting Defense Secretary Patrick Shanahan said in a new Indo-Pacific Strategy Report.

U.S. Pacific Fleet confirmed the Navy is exploring the viability of returning to Subic Bay in the Philippines with the use of bankrupt South Korean Hanjin Shipyard as a ship repair facility.

In 2011, President Barack Obama and Australian Prime Minister Julia Gillard agreed to the Marine rotational force and an increased U.S. Air Force presence in Australia.

The Marine contingent spends about six months training with Australian forces during the dry season and participates in exercises with other countries.

Kerry Gershaneck, a senior research associate at Thammasat University Faculty of Law in Thailand and an adjunct professor with University of Canberra’s Institute for Governance &Policy Analysis, said the Marine Corps deployment “visibly disproves the oft-repeated myth that America is retreating from Asia.”

Specifically, the rotations help counter a major theme of China’s that the United States is in irreversible decline and that China will soon be the regional hegemon, “so be smart and join China now,” said Gershaneck, a former Marine Corps officer.

The Australia deployment, though relatively small, “is a very visible show of America’s commitment to the Asia-Pacific region (that) pointedly says to friends and adversaries that America is here to stay,” he said.

The cooperation strengthens the security alliance by allowing Australian and American forces to routinely train and operate together.

“Enhanced interoperability lays the foundation for more effective cooperation during a crisis, and for long-overdue alliance enhancements such as establishment of Combined Maritime Amphibious Joint Task Forces to patrol the waters from Oceania up through northeast Asia,” Gershaneck said.

The aviation element for this year’s rotation is made up of 10 MV-22 tilt-rotor Ospreys and four AH-1Z Viper and three UH-1Y Venom helicopters — all from Hawaii, the Marines said.

At the same time, the U.S. and Australia are seeking closer ties with Pacific island nations to fend off growing influence from China.

Among key interests of the United States are the Federated States of Micronesia, the Marshall Islands, and Palau, whose presidents were invited to the White House for the first time in May.

Compacts of free association with the United States, which are up for renewal in 2023 and 2024, allow islanders from those areas to live and work in the United States and provide defense of the islands and exclusive military use rights.

While the U.S. Navy is seeking bombing training ranges on Pagan and Tinian islands in the Commonwealth of the Northern Mariana Islands, a palatial Chinese-funded casino is being built on nearby Saipan.

“While we affirm this alliance (with the United States), we want to ensure it also adapts,” Palau President Tommy Remengesau Jr. said during the White House visit. “We would welcome a larger U.S. military and law enforcement presence in Palau where our citizens, including veterans, can take a greater role in this partnership.”

Concerns have been raised about a possible Chinese military base in Vanuatu.

The U.S. and Australia agreed to partner with Papua New Guinea on the modernization of its Lombrum Naval Base.

The U.S. Navy also is looking at re-establishing a greater presence in the Philippines with the possible use of the former South Korean Hanjin Shipyard in Subic Bay as a potential repair and maintenance facility.

“No final decisions have been made,” said Cmdr. Nate Christensen, a spokesman for U.S. Pacific Fleet.

The U.S. closed its last base in the Philippines in 1992 after the country’s Senate rejected an extension.

Since the shipyard closed in February, retired Navy Capt. Brian Buzzell said a U.S. company has shown interest, “but the most active suitors are Chinese.”