A missile is launched from a US military HIMARS system during joint military drills at a firing range in northern Australia as part of Exercise Talisman Sabre, in Shoalwater Bay, July 22, 2023. [AFP]

Chinese surveillance ships are moving in to monitor the largest ever military drills involving the US and Australia. Defense officials expect the high-tech spy ships to remain outside Australia's territorial waters during "Talisman Sabre."

Thirty thousand military personnel from more than a dozen countries are participating in "Talisman Sabre," including troops from Canada, Germany, Japan, and the United Kingdom.

Australia is monitoring two Chinese surveillance ships. One is reported to be stationed in international waters off Shoalwater Bay in the state of Queensland where it's closely monitoring the drills.

Australia has made contact with the Chinese vessel, which gave a "courteous response" according to a senior Australian military officer.

Professor John Blaxland, head of International Security and Intelligence Studies at the Australian National University's Coral Bell School of Asia Pacific Affairs, believes that surveillance of the war games has become routine for China.

He told VOA that it will make Australia and its allies more alert to any potential threat in the future.

"China is a potential adversary," he said. "China is looking to collect information and that in doing so it plans to be in a position potentially to use it against us. That is having a very much a sobering effect on military practitioners in the army, navies and air forces of all those participating nations. So, yes, it is sobering, yes, it is plausible that it could be used against us and it is to a certain extent meant to intimidate. But it is in a sense part of healthy competition, really."

Drills are taking place in the states of Queensland, Western Australia and New South Wales, as well as the Northern Territory.

"Operation Talisman" began a decade ago. This year's event is the largest in terms of its geographical area and the number of countries taking part.

It includes amphibious landings, ground force maneuvers, air combat and maritime operations.

Soldiers from Australia, the United States, Japan, and South Korea carried out a joint live-fire demonstration at the Shoalwater Bay Training Area in Queensland on July 22 to launch this year's war games.

United States Secretary of the Navy Carlos Del Toro, said in a July 21 statement that the exercise "increases our ability to work together in the countering challenges we may face here in the Indo-Pacific region."

The drills are scheduled to run until early August.