The Trump administration on Monday said it would pause leases for five wind farms under construction off the East Coast, essentially gutting the country’s nascent offshore wind industry in a sharp escalation of President Trump’s crusade against the renewable energy source.

The decision injected uncertainty into projects that were collectively expected to power more than 2.5 million homes and businesses across the Eastern United States.

It left intact just two operational wind farms in U.S. coastal waters — one small project off Rhode Island that has been complete since 2016 and a larger project off New York that has been fully operational since 2023.

The five wind farms targeted on Monday had all obtained leases from the Biden administration. But citing unspecified national security concerns, the Trump administration said it would freeze those leases, effectively blocking construction or operations and jeopardizing billions of dollars that have already been invested.