United States and Australia started a joint military exercise called ‘Talisman Sabre’ which is set to go on for two weeks in the states of Northern Territory and Queensland.

The US and Australia kicked off a massive joint biennial military exercise on Sunday, with Japan taking part for the first time as tensions with China over territorial rows loom over the drills.

The two-week “Talisman Sabre” exercise in the Northern Territory and Queensland involves 30,000 personnel from the US and Australia practising operations at sea, in the air and on land.

About 40 personnel from Japan’s army – the Ground Self-Defense Force (JGSDF) – will join the American contingent, while more than 500 troops from New Zealand are also involved in the exercise, which concludes on July 21.

“It is a very, very important alliance,” Prime Minister Tony Abbott said Friday, referring to Australia-U.S ties.

“It’s a very important relationship and right now we are facing quite significant challenges in many parts of the world but particularly in the Middle East,” Abbott added in Sydney on board the USS Blue Ridge, which is taking part in the exercises.

The war games, being held for the sixth time, come as China continues to flex its strategic and economic muscle in the region.

The US has been pursuing a foreign policy “pivot” towards Asia, which has rattled China, and is rotating Marines through northern Australia — a move announced by President Barack Obama in 2011.

Australia has stepped up its relationship with Japan in recent years and last July, Abbott described Prime Minister Shinzo Abe as “a very, very close friend” during a state visit to Canberra.

The Australian government is also considering buying Soryu-class submarines from Japan, which Lee, the China expert, said would be fully integrated with U.S. weapons systems.

Japan’s involvement has in part also been driven by domestic politics, Asian security specialist Craig Snyder of Deakin University said, as Abe’s right-wing government tries to increase Tokyo’s participation in the regional security arena.