West Australian Premier Roger Cook is on a five-day mission to the UK to strengthen the AUKUS agreement and advocate for the construction of more nuclear-powered submarines in Western Australia.

Accompanying Cook is Defence Industries Minister Paul Papalia, as they aim to enhance WA's position in the global defence sector.

The visit comes in the wake of UK Prime Minister Sir Keir Starmer's announcement to build up to 12 additional submarines over the next decade.

WA's defence manufacturing sector currently supplies parts for Australia's submarine fleet and is actively seeking to enter the supply chains for US Virginia-class and UK Astute-class submarines.

Cook emphasizes the importance of diversifying WA's economy through the defence industry, which is expected to attract international investment and foster local business growth.

The West Australian government anticipates that the defence sector will become the state's second-largest industry, overtaking agriculture, and aims to lobby for UK Astute-class submarines to be built locally during the talks.

Minister Papalia highlighted that WA's local businesses are well-positioned to support the construction and maintenance of Astute-class submarines, benefiting both WA and its AUKUS partners.

If the AUKUS agreement is implemented, it will lead to the rotational presence of US and UK nuclear submarines at Perth’s HMAS Stirling starting in 2027.

This mission also underscores WA’s clean energy ambitions, promoting the state's renewable energy potential alongside its defence industry capabilities.

During the visit, the WA Government will host a roundtable in London with defence industry leaders and meet with UK officials, including Defence Procurement Minister Maria Eagle.

As part of their mission, Cook and Papalia plan to visit His Majesty’s Naval Base in Devonport, the only nuclear refuelling site in the UK.

Cook stated that this initiative is part of the broader 'Made in WA' plan aimed at diversifying WA’s economy beyond reliance on natural resources.