The deployment of the USS Colorado marked a significant milestone in building joint US-Australia-UK deterrence in the Pacific under the Aukus defence pact. (Wiki pic)SYDNEY: 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 377-foot (115-metre) Virginia-Class submarine, armed with land-attack missiles and sophisticated torpedoes, will sail to the new Australian base in late 2027, officials said Tuesday.

The deployment is 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 buildup 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.