The U.S. President has blocked an attempt by a Chinese-owned company to build wind farms in Oregon close to a navy site used for testing drones and electronic warfare training.
Barack Obama said in a statement he had decided that Ralls, the company owned by two Chinese executives that is seeking to build the wind farms, "might take action that threatens to impair the national security of the United States."
However, the administration argued that the move did not reflect a general opposition to Chinese investment in the U.S.
It said in a statement: "The President's decision is specific to this transaction and is not a precedent with regard to any other foreign direct investment from China or any other country."
In a detailed order, the President told Ralls it had to sell its holdings in the wind farm projects within 90 days, along with all associated intellectual property and contracts, and remove all its equipment and structures, including concrete foundations, from the sites within 14 days.
Ralls' plans caused concern in the U.S. government because one of its four wind farm sites is within the airspace used by the naval training facility and the other three are within eight kilometres of that airspace.
The facility is used for training in air-to-air combat, bombing and electronic warfare, and for testing drones, among other operations.
The President's decision upholds an earlier order from the Committee on Foreign Investment in the U.S. (CFIUS), an inter-agency government body, for the company to stop construction work on the project.
Ralls had taken the unusual step of challenging the order in court, and last week won an agreement from the government that it could carry on some building work pending a decision from the President, who has final authority.
The U.S. government said last week that the President would make his ruling by Sept. 28.
The Treasury Department, which chairs CFIUS, said in its statement that the decision "demonstrates the administration's commitment to protecting national security while maintaining the United States' longstanding policy on open investment."
It is very rare for CFIUS orders to require a presidential decision to enforce them. The last time was in 1990 when companies backed by the Chinese government attempted to buy Mamco Manufacturing, a Seattle-based aerospace company, but were blocked by President George H.W. Bush.