WASHINGTON, July 8 (UPI) -- A new U.S. government program is designed to detect cyberattacks on crucial agencies in the private and public sectors, sources tell The Wall Street Journal.

The expansive program called "Perfect Citizen" would protect private companies and government agencies running crucial infrastructure, such as the electricity grid and nuclear power plants, the Journal said.

The surveillance would be conducted by the government's chief eavesdropping agency, the National Security Agency, and would rely on sensors deployed in computer networks. The Journal said the system would be triggered by activity suggesting an impending cyber assault, though sources said the program would not consistently monitor the whole infrastructure system.

Raytheon Corp. recently won a classified contract for the initial phase of the program, valued at up to $100 million, a source told the Journal. Both the NSA and Raytheon declined to comment.

The Journal said some private and government officials say the program is an intrusion by the NSA into domestic affairs, while other officials say the job can only be done by the NSA.

The newspaper said U.S. intelligence officials are increasingly worried about what appears to be Chinese and Russian surveillance of computer systems that control U.S. infrastructure.