Ministers have chosen the Welsh island of Anglesey as the location for the UK’s first “mini” nuclear power stations.

Wylfa on Anglesey has beaten Oldbury in Gloucestershire as the government’s preferred location for three pioneering small modular reactors (SMR) which are to be built by Rolls-Royce.

But Donald Trump’s ambassador warned the decision threatened the UK’s relationship with the US after he slammed the move as “extremely disappointing”.

Warren Stephens had urged the UK government to commit to a large-scale nuclear power station at Wylfa on Anglesey.

The American nuclear developer Westinghouse and the US construction group Bechtel had proposed building the plant.

Mr Stephens said: “We are extremely disappointed by this decision, not least because there are cheaper, faster, and already-approved options to provide clean, safe energy at this same location. If you want to get shovels in the ground as soon as possible and take a big step in addressing energy prices and availability, there is a different path, and we look forward to decisions soon on large scale nuclear projects. As I have repeatedly said, we want the UK to be the strongest possible ally to the United States, and high energy costs are an impediment to that.”

The nuclear investment in Wales could lead to supporting 3,000 new good jobs in the local economy, the Department for Energy Security and Net Zero (DESNZ) said.

Prime Minister Sir Keir Starmer added: “Britain was once a world-leader in nuclear power, but years of neglect and inertia has meant places like Anglesey have been let down and left behind.

“Today, that changes. We’re using all the tools in our armoury – cutting red tape, changing planning laws, and backing growth – to deliver the country’s first SMR in North Wales.

“This government isn’t just reversing decline, it’s delivering thousands of future-proofed jobs, driving billions in investment, and providing cheaper energy bills in the long term.

“That’s national renewal in action: powered by British talent, powered by nuclear, and powered by a Government that’s delivering for working people.”

Sir Keir Starmer has vowed to “push past the nimbyism” to ensure deployment of several new smaller atomic plants.

The UK’s first SMRs, mini nuclear reactors which are smaller and quicker to build than some traditional nuclear power stations, are expected to deliver power for the equivalent of around three million homes as part of the government’s clean energy plans.

No full-scale commercial SMRs have yet been deployed anywhere in the world. However, Rolls-Royce is hoping that its first one will generate a steady supply of low-carbon electricity by the mid-2030s.

Chris Cholerton, chief executive of Rolls-Royce SMR, said: “This is a tremendous opportunity not just for North Wales but for the whole country, as we establish an enduring supply chain that will enable our fleet deployment in the UK and a large export programme, starting in Czechia.

“We will deliver nuclear power very differently by utilising modularisation and a high level of factory build, therefore minimising the impact on local people from infrastructure delivery. We are excited to be working with the local community to create jobs and growth.”

Wylfa is an old nuclear power station off the coast of Anglesey, in north west Wales.

It was built in the 1960s and first began generating electricity in 1971, employing thousands of workers.

In 2015, Wylfa’s last reactor was closed down and it began the long process of being decommissioned, ending 44 years of operations at the site.