OpenAI has pulled out of a UK investment pledge, which included a promise to deploy thousands of GPUs at Nscale facilities.

The generative AI company was among a number of US firms that last September promised to invest £31 billion ($41.6bn) in UK AI projects, including data centers.

At the time, OpenAI said that it planned to rent space in several as yet unbuilt Nscale data centers, initially “exploring” the uptake of up to 8,000 GPUs.

Now, the company said that it was pausing such plans due to high energy costs and unspecified regulatory challenges.

“We continue to explore Stargate UK and will move forward when the right conditions such as regulation and the cost of energy enable long-term infrastructure investment,” OpenAI said in a statement.

Industrial energy prices in the UK are among the highest in the world. One of Nscale’s data centers was set for the new ‘AI Growth Zone’ in Cobalt Park, in the North East, where the UK government has sought to make regulatory approval and energy connections faster.

Stargate has more broadly seen setbacks and delays, with the company increasingly turning to cloud contracts to simplify its compute portfolio as well as minimize its balance sheet ahead of a planned IPO.

In December, OpenAI hired former UK Chancellor George Osborne to lead its global Stargate data center expansion.