London: The United Kingdom has awarded three UK companies a 4 billion pound ( USD 4.9 billion) contract to design and manufacture a nuclear-powered attack submarine as part of the country’s AUKUS programme with Australia and the United States, Al Jazeera reported.

The first of the submarines will be delivered into service in the UK in the late 2030s and the first Australian ones will follow in the early 2040s.

The SSN-AUKUS program aims to enhance the capabilities of the UK, Australia, and the US to counter regional security challenges, particularly from China in the Asia-Pacific region, Al Jazeera reported.

UK’s Defence Ministry in a statement on Sunday said that the contract with BAE Systems, Rolls-Royce and Babcock “represents a significant milestone for both the UK and the trilateral AUKUS programme as a whole”.

It said that the new submarines, known as SSN-AUKUS, “will be the largest, most advanced and most powerful attack submarines ever operated” by the Royal Navy and will “combine world-leading sensors, design and weaponry in one vessel”.

The plans for SSN-AUKUS were unveiled in March by the leaders of Australia, the UK and the US and came as the three countries ramped up their efforts to counter China in the Asia Pacific region.

The nuclear-powered vessels – which have far greater stealth and range and mark the first time Washington has shared nuclear-propulsion technology with a country other than the UK – represent a significant upgrade to Australia’s current diesel-powered fleet, as per Al Jazeera.

Previously, Australian Defence Minister Richard Marles described the AUKUS deal as “the biggest step forward in our military capability that we’ve had since the end of World War II”.

Through the AUKUS, Washington intends to sell Canberra up to five of its Virginia-class nuclear-powered submarines in the early 2030s.

It will also see US and UK submarines deployed in Western Australia as soon as 2027 to help train Australian crews.

Analysts say the AUKUS programme will strengthen deterrence in the face of China’s increasingly assertive actions in the Pacific, including in the South China Sea where it has built military bases on disputed outcrops and reefs.

A senior fellow for Indo-Pacific security at the Carnegie Endowment for International Peace think tank, Ashley Townshend, wrote: “As highly stealthy platforms, SSNs’ ability to operate in contested waters, hunt Chinese warships and submarines, control strategic sea lanes and chokepoints, and project power with long-range cruise missiles make them one of the most effective ways to complicate Chinese military planning and give Beijing a reason to take pause before using force.”

“The fact that US, UK, and, in time, Australian SSNs will be operating as a combined force—with Aussies also embedded on American and British subs—raises the spectre of horizontal escalation by forcing Beijing to consider the prospect that military action against any SSN, or the submarine base itself, could trigger the involvement of all three nations,” he added.