US Energy Secretary Rick Perry has issued $3.7 billion (£2.8bn) of new funding to keep the Vogtle nuclear power plant project afloat.
The federally-backed loan guarantee will help support the completion of the facility in Georgia and follows years of cost overruns and delays.
It will help finish building Units 3 and 4 at the nation’s only active advanced nuclear energy construction project.
The government says the new nuclear reactors will provide more than 17 million megawatt-hours of low carbon electricity every year.
The new injection of money into the programme, which is being carried out by Southern Company and its partners, means US taxpayers have now contributed around $12 billion (£9.1bn) to the plant.
With an original budget of $14 billion (£11bn), Vogtle is now expected to cost a total of $28 billion (£22bn).
Mr Perry made the announcement after a tour of the site – he also announced the facility was “critically important” in bringing the nation’s nuclear industry back to life and said: “A strong nuclear industry supports a reliable and resilient grid and strengthens our energy and national security.”
He noted the project also served the role of training a highly skilled nuclear workforce and developing a supply chain for the future.