As part of its continuing modernization program, the Australian military is upgrading its naval air defene capabilities which will allow them to better integrate with US air defense:

Under the SEA 4000 Air Warfare Destroyer program, Australia plans to replace its retired air defense destroyers with a modern system that can provide significantly better protection from air attack, integrate with the US Navy and other Coalition partners, offer long-range air warfare defense for Royal Australian Navy task groups, and help provide a coordinated air picture for fighter and surveillance aircraft. Despite their name and focus, the ships are multi-role designs with a “sea control” mission that also includes advanced anti-submarine and surface warfare capabilities.

Spain’s Navantia made an A$ 11 billion clean sweep, winning both the A$ 3 billion Canberra Class LHD and the A$ 8 billion Hobart Class Air Warfare Destroyer contracts. The new AWD ships were scheduled to begin entering service with the Royal Australian Navy in 2013, but that date has now slipped to 2014-2015. Recent updates involve a number of smaller contracts and progress reports, as well as the resolution of A$ 450 million worth of Australian shipbuilding contracts…  [Defense Industry Daily]