The suspension was the latest blow for offshore wind developers that have faced repeated disruptions to their multi-billion-dollar projects under US President Donald Trump, who has said he finds wind turbines ugly, costly and inefficient.
State officials, Democratic politicians, offshore wind companies, and industry trade groups slammed the move as unjustified.
The US Department of the Interior said the decision was the result of complaints by the Pentagon that the movement of huge turbine blades for offshore wind projects, as well as the highly reflective towers that hold them up, cause radar interference that can make it hard to identify and locate security threats.
The pause will give relevant federal agencies "time to work with leaseholders and state partners to assess the possibility of mitigating the national security risks posed by these projects," the department said in a statement.
"The prime duty of the United States government is to protect the American people," Secretary of the Interior Doug Burgum said in the statement.
The pause will affect Danish energy firm Orsted's Revolution Wind and Sunrise Wind projects, Avangrid and Copenhagen Infrastructure Partners' Vineyard Wind 1 project, Dominion Energy's Coastal Virginia Offshore Wind, and Equinor's Empire Wind 1 project, according to the statement.
Dominion said the suspension will threaten grid reliability for its Virginia customers, including military bases and data centres powering artificial intelligence.
"These electrons will power the data centres that will win the AI race, support our war fighters, and build the nuclear warships needed to maintain our maritime supremacy," the company said.
Orsted said its projects were in advanced stages and had been preparing to power around one million homes across three states from next year.
"Orsted is evaluating all options to resolve the matter expeditiously, together with its partners," the company said.
Equinor said it was also evaluating the suspension. Copenhagen Infrastructure Partners was not immediately available for comment.
New York Governor Kathy Hochul and Connecticut Attorney General William Tong said in separate statements that US states affected by the freeze were reviewing their options.
"The Trump administration will look for any excuse to continue its assault on clean energy - and the thousands of good-paying jobs these projects bring - but there is no credible justification for this stoppage," Hochul said.
The National Ocean Industries Association, a trade group representing offshore wind developers, urged the administration to end the pause quickly.
"The regulatory process involves a rigorous framework for assessing the national security implications of proposed projects, and every project under construction has already undergone review by the Department of Defence with no objections," NOIA President Erik Milito said.
