OpenAI is close to leasing a $500 billion data center in southern Ohio that could become one of the largest artificial intelligence (AI) facilities ever built.

The ChatGPT maker is also in talks with Nvidia for a $250-billion financial backstop, which would help secure financing for the project, according to people familiar with the discussions.

The facility, backed by 10 gigawatts of power, is being developed by SoftBank as part of a US-Japan investment partnership. While Microsoft, Google and other companies have submitted bids, OpenAI is emerging as the leading tenant.

The project still requires approval from US commerce secretary Howard Lutnick.

Construction is planned on the site of a former uranium enrichment plant in Piketon, Ohio, with the first phase targeted for completion in 2028.

The proposed deal underscores the AI industry’s unprecedented spending on data centers, although analysts continue to warn about the risks of taking on massive debt to fund the AI boom.