"Washington will have a very serious set of conversations about what this means for its expectations of friends and allies," the Canberra-based defence expert said.

Mr Jennings noted the weapon system reportedly deployed by China was only a generation behind that used to shoot down a Malaysian Airlines flight over eastern Ukraine in July, 2014.

However, China has refused to confirm or deny the reports insisting only that it has the right to defend its sovereignty and Foreign Minister Julie Bishop, who has been in Beijing for a two-day visit, said she would wait until the claims had been verified.

"It is a contested claim," she told reporters in Beijing, adding that China hadn't acknowledged the missiles were there.

"Australia is keen to understand precisely what China's intentions are in relation to the South China Sea," Ms Bishop said.

"Any militarisation of the islands would be of serious concern but the report is in dispute."

Chinese commentators and experts have accused Washington of inflaming the situation.

"We wouldn't make this defensive move if the US hadn't sent its bombers flying above our islands," said Liu Qing, from the China Institute of International Studies, a think-tank linked to the Foreign Ministry.


Mr Liu, who has recently returned to Beijing from Canberra, where he worked as a diplomat, said the Australian government should play a mediating role.

"Facing these aggressive moves from the US, Australia should advise Washington to ease tensions instead of pouring fuel on the fire as it is not helpful to maintaining peace and security in the region."

The hawkish state-owned newspaper The Global Times said in an editorial the US, "an outsider", was directly responsible for militarisation of the region. It said the US was advocating for allies, Japan and Australia, "to join its military navigation."

"Once the US repeatedly sends warships to make provocations at Chinese islands and threatens the security of Chinese people and facilities on the islands, more military equipment should be deployed to counter US provocations," the editorial said.

The South China Sea is subject to a complicated web of territorial disputes involving China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan. Australia has said repeatedly it doesn't take sides but advocates for the disputes to be resolved peacefully.

Rebecca Fabrizi, a researcher at the Australian National University who specialises in Chinese foreign policy is not convinced high-profile "freedom of navigation" operations are the right policy option for Canberra.

"We need to get China back to the negotiating table with the other rival claimants," she said.