Australia to host USS Colorado as first US nuclear submarine under Aukus pact

The Pentagon has assigned the USS Colorado as the first US nuclear-powered attack submarine to join a rotating force to be based in Western Australia.

The 115-metre (380-foot) Virginia-class submarine, armed with land-attack missiles and sophisticated torpedoes, would sail to the new Australian base in late 2027, officials said on Tuesday.

The deployment was a “significant milestone” in building up a joint US-Australia-UK deterrence in the Pacific under their Aukus defence pact, the allies said in a joint statement.

The defence agreement, seen as a response to China’s military build-up in the region, aims to equip Australia’s navy with a fleet of stealthy nuclear-powered submarines and expand military cooperation between the three allies.

Australia does not permit foreign military bases on its soil, but hosts US Marines for exercises for six months a year in the northern city of Darwin.

The rotating force of nuclear-powered submarines – known as Submarine Rotational Force-West – is to be hosted at a naval base in Western Australia, HMAS Stirling.

The base is projected to host up to five fast-attack submarines – four from the United States and one from the UK – on a rotational basis. It would help Australia prepare for operating and maintaining its own nuclear-powered submarines while supporting its allies’ deployments and maintenance, the three countries said.

The rotating submarine force was the first “really big milestone” under the Aukus agreement, Australian Defence Minister Richard Marles told news channel News24.

“It’s on track,” Marles said. “There are American personnel at HMAS Stirling right now readying the site for this.”

The Aukus submarine programme lies at the heart of Australia’s defence strategy and could cost up to US$235 billion over 30 years, according to government forecasts.

French defence ⁠group Thales said ⁠on Monday ⁠it had opened a sonar facility in the Western Sydney suburb of Rydalmere to produce ‌and maintain towed array sonar systems for the Australian military’s submarines, ships and maritime platforms.

The site, co-funded by Thales Australia and ⁠the Commonwealth, will supply sonar for Hunter-class ‌frigates, Collins-class submarines and the BlueSentry autonomous system. Investment is ‌described as multimillion Australian dollars but no ⁠specific ⁠figure was disclosed.

Local sustainment is intended ‌to cut offshore maintenance periods and extend deployment ‌times for ‌Australian intelligence, surveillance and reconnaissance operations.

Thales owns about 35 per cent of ⁠Naval Group, which lost a submarine contract ⁠with Australia in 2021 when Canberra cancelled the programme in favour ‌of the ‌Aukus pact, triggering a diplomatic dispute between France and Australia.