As US military presence ramps up in the north, experts say one of Australia's closest Asian neighbours is growing wary that the US's expanded presence could bring rising tensions to the region.

“A lot of countries in our region, whether it’s the Pacific or South-East Asia, they are predominantly concerned about development, about economics, about nation-building — not necessarily about what a rising China means for their defence or military interests,”

On Saturday, Malaysia joined Indonesia in raising alarm bells about the military build-up in the region and the impact that the AUKUS pact, which includes Australia acquiring nuclear-propelled submarines, could have on regional stability.

Indonesia had for decades pursued an “aktif bebas”, or free and independent foreign policy.

“It’s never going to side with a partisan international alliance, so of course they will be pushing back.”

“They’re also going to be miffed because they were not consulted, just like on the Marines based in Darwin [announced a decade ago]. Despite that they won’t have a real problem, it’s just not in their interests or instincts to side with us.

“[Indonesian President] Jokowi, [Foreign Minister] Retno, [Defence Minister] Prabowo get this, they’re also miffed at what China is doing. They could be domestically wedged by their opponents so no one wants to say it publicly – this is classic south-east Asian behaviour. But like us, they have to balance economic interests and security concerns.”

“ASEAN governments are acutely aware of that and are worried that external powers are creating new architecture that doesn’t include them like the Quad and potentially AUKUS too